SONATA FOR TWO PIANOS in F MINOR, OP. 34b (after the Piano Quintet, Op. 34)
Recording: Martha Argerich & Alexandre Rabinovitch, Pianos [Teldec 4509-92257-2]
Published 1872.  Dedicated to Her Royal Highness Princess Anna of Hessen.

When Brahms drafted an F-minor string quintet with two cellos (following Schubert’s example) in 1862 and submitted it to his friends for criticism, Joseph Joachim found that the extraordinarily rich and dramatic content overtaxed the medium of strings alone.  It appears that, while not heeding other criticisms about the content, Brahms was convinced that the scoring was not right.  Even when he did come back, much later, to the string quintet form, he used the less challenging Mozart combination of two violas instead of two cellos.  The first revision was what we now know as the Sonata for Two Pianos.  It is unclear whether he meant this to be the final form.  Brahms would come to use two pianos as an arrangement medium for larger works (such as the symphonies) to help familiarize musicians and music lovers with their sound.  The two-piano predecessor to what would become the Piano Quintet is on a different level from these arrangements.  Not only did it precede the final form, but Brahms published it six years later with a separate sub-opus number.  He and Carl Tausig, a brilliant virtuoso student of Liszt (who sadly died at age 29), performed the two-piano sonata publicly in Vienna in 1864, and it was well received.  Clara Schumann was not satisfied with it, however, and considered it an “arrangement,” spurring Brahms to produce the final piano quintet version.  But it is evident that he still considered the duo sonata version to have worth, as shown by its later publication.  Like the Quintet, it was dedicated to Princess Anna of Hessen, who was very fond of the two-piano version.  In thanks for the dedication, she presented him with Mozart’s manuscript of the great G-minor Symphony to add to his prized collection.  It is important to note that neither of the two piano parts matches the piano part from the quintet.  The scoring of each version is thus largely independent.  Some stretches from one piano part or the other were directly transferred into the quintet version.  Other passages were re-scored for strings alone.  Brahms usually “reversed” the piano parts when analogous music returned (such as in the recapitulation of the first movement, the A’ section of the second, and the reprise of the fourth).  In the quintet version, passages were also re-scored (including a reversal of piano and strings) when they returned.  It could be argued that certain passages actually work better with the two-piano medium.  At the first passionate eruption after the quiet opening of the first movement, the percussive nature of the punctuating chords is not quite as pronounced when played by strings.  Particularly in the scherzo movement, in the passages where the second theme has its long-short rhythms “filled in,” the power of four hands pounding on two keyboards is breathtaking.  But the slow movement is certainly more effective with strings, as is the introduction to the finale.

The general practice in these guides has been to include important alternate versions of works within the same guide (see, e.g., Opp. 12, 18, 39, 52, 65, 120 Nos. 1 & 2).  Given the history of the two-piano and piano quintet versions of this music, however, as well as the scope of the differences (arising from neither piano part of the sonata matching that of the quintet) and the size of the piece itself, an exception is made in this case and a separate guide constructed for each version.  The guide for the quintet provided a template for the following guide, but an effort has been made to treat the sonata independently from the quintet, without reference to the quintet scoring (or to any string instruments) except when to do so would be of particular interest (such as the “extra” measures in the two-piano version of the first movement).  Care has been taken to clearly differentiate between the two piano parts.

ONLINE SCORE FROM IMSLP (First Edition from Brahms-Institut Lübeck)

ONLINE SCORE FROM IMSLP (From Breitkopf & Härtel Sämtliche Werke)

1st Movement: Allegro non troppo (Sonata-Allegro form). F MINOR, 4/4 time.
0:00 [m. 1]--Theme 1.  Both pianists, spread over three octaves, play the distinctive unison main idea.  It is an ominous winding figure that begins with an upbeat and then a short-long rhythm.  Downward-arching arpeggios follow, emphasizing half-step motion.  As Piano II reaches the last such gesture, Piano I holds the chord it outlines on the unresolved preparatory “dominant” harmony.  Brahms then indicates a fermata, or hold, creating suspense before the onslaught that follows.
0:15 [m. 5]--Piano I suddenly breaks into a series of passionate arpeggios in octaves, with the hands an octave apart, punctuated by chords and bass octaves from Piano II that again emphasize half-step motion.  The arpeggios have the same shape as the ominous first idea.  After two short one-measure interjections, a longer one follows, with Piano II almost violently underscoring the forceful motion in Piano I.  This continues for three measures.  In the third of these, the left hands of both pianists reverse roles so that that of Piano II is playing the lower octave on the arpeggios.  Piano II then holds a chord while Piano I, again in octaves, rushes upward in a dramatic, sweeping arpeggio.
0:28 [m. 12]--Piano II now continues with the same passionate intensity on a new version of the main idea.  Both hands are in octaves, the right hand playing the theme and the left providing low bass support.  Piano I, meanwhile, plays heavy, slower descending arpeggios, still in octaves.  The downward arpeggios of Piano II deviate from the initial statement, and the long-short rhythm is more pervasive.  After four measures, the right hand of Piano I inserts a rapid upward arpeggio as Piano II continues with its last two downward gestures on a repeated, accented half-step descent.
0:39 [m. 17]--The right hand of Piano I repeats its rapid upward arpeggio, and then both pianos erupt into another passionate outburst.  The right hand of Piano II plays intense downward half-steps and whole steps in octaves while its left hand plays rapidly arching arpeggios that cascade downward.  As Piano II lands on the downbeat, Piano I inserts its own interjections of the dramatic arpeggios in octaves.  After two measures, its hands begin to play the arpeggios in alternation.  Piano II, meanwhile, begins to play heavy chords on strong beats after descents from upbeats.
0:44 [m. 20]--The left hand of Piano II begins to play descending triplets in octaves against its heavy right-hand chords and the arpeggios in Piano I.  A huge cadence gesture in both instruments ends the main theme complex.
0:51 [m. 23]--Transition.  The transition has its own melody, but it is derived from elements of Theme 1.  Piano I leads a yearning, expressive melody with a prominent dotted (long-short) rhythm as well as half-step motion.  The right hand plays both the melody and a smooth counterpoint, while the left hand and the right hand of Piano II, in alternation, add extremely expressive, almost sighing octave leaps with downward resolutions.  These figures are in triplet rhythm.  The left hand of Piano II adds solid bass notes on the strong beats.
1:00 [m. 27]--The melody briefly passes to Piano II, and both left hands and the right hand of Piano I take the sighing triplet leaps.  After two measures, the melody returns to the Piano I, with only its left hand playing the triplet leaps.  At this point, Piano II largely abandons these leaps and turns to urgent repeated chords on the triplet rhythm in groups of three or six, with a solid bass in its left hand.  The intensity begins to build.  An inflection of the melody is used to propel the key toward C-sharp minor, where Theme 2 will be set.  A huge buildup and increase of activity leads directly into the marching motion of Theme 2.  The Piano II bass begins the oscillating triplet motion that will underpin this theme, rapidly diminishing in a two-bar bridge.
1:15 [m. 35]--Theme 2.  The oscillating triplet motion in the bass of Piano II—in which three-note figures move up a half-step on the middle note—dominates the second theme.  The first note of each figure is supported by a low “pedal bass” C-sharp.  The melody itself begins with a jerky figure in Piano I and the right hand of Piano II.  It continues with an upward-reaching, harmonized line that the hands of Piano I play in octaves.  The right hand of Piano II plunges down against it (C-sharp minor). 
1:24 [m. 39]--Piano II presents a new expressive phrase sotto voce.  It uses a triplet figure and half-steps, and bears a resemblance to the transition melody.  The hands are in contrary motion.  Under this, both hands of Piano I move to the oscillation, playing in octaves.  Breaking from the oscillation, Piano I follows the Piano II phrase with an upward arpeggio in octaves that turns to major as Piano II plays soft held chords.  This sequence, the Piano II phrase and then the Piano I arpeggio, is restated a half-step higher, turning briefly to D major.
1:42 [m. 47]--The first part of the theme, with the jerky melody and upward-reaching line, is expanded.  Shifting instantly back to C-sharp minor, the Piano II bass oscillation restarts.  The theme itself is initially played by the left hand of Piano I and the right hand of Piano II in octaves.  The Piano I right hand adds descending chords.  The expansion comes after the third measure, where the rising line presses upward even more.  The right hand of Piano II takes it over, still in octaves.  The left hand of Piano I joins the chords of its right hand.  The bass’s anchor on C-sharp drops down to B.
1:50 [m. 51]--Piano I takes over the rising line, stretching it out even more and briefly touching on A major/minor.  The bass of Piano II, meanwhile, moves from the oscillation to broken octaves without a persistent “pedal” note.  Its right hand plays wide arpeggios in triplets.  Piano I rounds off the rising line with a soaring melody that slowly descends to a cadence in C-sharp minor.  This soaring line and cadence are echoed by Piano II, while Piano I plays strong harmonies.
2:02 [m. 57]--Piano II returns to the expressive phrase with the triplet figure, altering it slightly by approaching the triplet from below.  The left hand offers support in longer chords.  Under it, Piano I returns to material from Theme 1, a variant of the “passionate arpeggios,” passed from left to right hand.  These are transformed into a quiet, skittering accompaniment that hints at the major key even while Piano II uses poignant chromatic notes.  After two measures, Piano I turns back to the soaring cadence line, now in major, with the right hand imitating the left.  Piano II adds pulsating triplets beginning off the beat.
2:10 [m. 61]--The left hand of Piano II repeats the preceding phrase with the long supporting notes, now harmonized, in the right hand.  The Piano I arpeggios follow the same pattern, but are now on the harmony of A minor/major instead of C-sharp.  Both right hands then take the soaring cadence line, Piano I following Piano II, but it is changed to incorporate two soaring gestures.  The left hand of Piano II plays the pulsing triplets while that of Piano I adds a solid bass.  The key moves from A back to C-sharp, now more clearly major.
2:19 [m. 65]--A variant of the expressive phrase with the triplet figure in C-sharp major is passed from the right hand of Piano I to that of Piano II.  The rapid arpeggios, with accompanying rising lines, take over first in Piano II, then Piano I, each while the other has the expressive phrase.  While this passage begins dolce e leggiero, it quickly becomes agitated, rising in volume.  Piano II then breaks into an extremely heartfelt version of the soaring cadence line while its left hand continues the variant of the phrase with the triplet figure.  The Piano I arpeggios in the right hand become wider and more intense, while the left hand supports them with chords and some doubling of the Piano II bass.  The soaring line is stated twice, extended the second time into a beautiful cadence with aching chromatic notes.
2:38 [m. 74]--Closing section.  With C-sharp major firmly established, Brahms uses the cadence to change the notation to the more convenient D-flat major.  This also allows him to return to the four-flat key signature of the home key.  The cadence is followed by a quick downward slide to the “dominant” note in bass octaves.  Piano II then holds long notes.  Piano I follows with arching arpeggios, then a new, somewhat martial dotted rhythm.  Piano II echoes the marching dotted rhythm in descending lines, coming to a full cadence.
2:47 [m. 78]--The previous pattern is given again, but now the quick downward slide leads to the more unstable “leading tone” instead of the “dominant.”  The Piano I arpeggios soar higher in the right hand and lower in the left.  The martial dotted rhythm is expanded.  The first Piano I statement emphasizes the preparatory “dominant” harmony.  The descending  Piano II echo comes to a cadence, but a less convincing one.  Piano I adds an extra second echo to make it more conclusive.
2:58 [m. 83]--The descending dotted rhythms of the “echo” are straightened out into groups of three descending harmonized three-note patterns.  These obscure the bar line, with the third pattern of each group beginning on an eighth-note upbeat.  The first such group is in Piano II, with the right hand harmonized in thirds and the left playing wide upward arpeggios.  Piano I overlaps and follows at a higher level.  Piano II has a third overlapping group that is lower than the first one.  This third group is not in the quintet version, which conflates the pitches and harmonies into two groups.  Thus, this passage is a measure longer here.  The intensity builds over these groups.  Finally, in a fourth overlapping group (corresponding to the third group of the quintet version), the two pianos join together, building over rich, chromatic harmony.
3:07 [m. 87]--The descending patterns suddenly double the lengths of their notes, restoring the sense of meter.  The first lengthened three-chord pattern immediately follows the last, richly harmonized faster group.  The second pattern is separated from the first by a rest on the downbeat.  The intensity begins to wane with this second longer pattern, and long-short chords support the three-note descent in the right hand of Piano I.  The two patterns are repeated an octave lower with thinner harmonies, and the volume continues to diminish.  Both patterns begin after a downbeat rest.  This leads to a full close in D-flat major with two quiet weak-beat pulses.
3:20 [m. 92a]-- First ending.  The five-measure first ending continues the off-beat pulses.  The first of these is simply a third repetition of the closing D-flat harmony in Piano II, but Piano I adds an ominous rising line in octaves against it.  This already suggests the home key of F minor.  Another group of three off-beat pulses follows in Piano II, still on D-flat.  Overlapping the last pulse is another Piano I line in octaves, a third higher than the first one.  A third group of three pulses drops its bass by a half-step, creating an F-minor harmony.  Again, the ominous Piano I line coincides with the third pulse and is a third higher, the hands now two octaves apart (as in the opening main idea).  Its second note takes the place of the upbeat leading into the main idea, and the repeat leads into its downbeat.
3:33 [m. 1]--First unison statement of main idea ending in the fermata.
3:46 [m. 5]--Passionate arpeggios and violent chords, as at 0:15.
3:59 [m. 12]--Main theme with heavy Piano I arpeggios, as at 0:28.
4:10 [m. 17]--Passionate outburst with stepwise descents and alternating arpeggios, as at 0:39.
4:16 [m. 20]--Descending bass octave triplets, continuing arpeggios, and cadence gesture, as at 0:44.
4:22 [m. 23]--Transition.  Yearning Piano I melody and expressive octave leaps in triplet rhythm, as at 0:51.
4:31 [m. 27]--Piano II statement of melody, buildup, and motion to C-sharp minor with bridge, as at 1:00.
4:47 [m. 35]--Theme 2.  Oscillating bass triplets under jerky melody and upward-reaching line, as at 1:15.
4:56 [m. 39]--Expressive phrase with triplet rhythm moving to major, then repetition in D, as at 1:24.
5:15 [m. 47]--Expansion of theme with longer rising line and bass motion down from pedal, as at 1:42.
5:24 [m. 51]--Continuation of rising line, Piano II arpeggios, and soaring arch to cadence, as at 1:50.
5:36 [m. 57]--Piano II statement of expressive phrase, Theme 1 material, and arching cadence, as at 2:02.
5:45 [m. 61]--Left hand repetition of expressive phrase in A, then expanded cadence in major, as at 2:10.
5:54 [m. 65]--Variant of expressive phrase over arpeggios, then buildup to cadence, as at 2:19.
6:13 [m. 74]--Closing section.  Downward slides, arching arpeggios, and martial dotted rhythms, as at 2:38.
6:22 [m. 78]--Repetition of pattern with expansion of dotted rhythms, as at 2:47.
6:33 [m. 83]--Three-note groups in straight rhythm, obscuring bar lines and building in intensity, as at 2:58.
6:42 [m. 87]--Longer three-chord patterns settling down to close in D-flat major, as at 3:07.
6:55 [m. 92b]--Second ending.  The material is similar to the first ending, but the rising Piano I octave patterns begin a third higher than before, initially suggesting A-flat minor instead of F minor.  The second and third of these lines begin on the same notes where the previous ones ended (instead of a third higher). The third group of Piano II pulses has a new bass on B-natural, creating a highly dissonant “diminished” chord.  The third Piano I line is only one octave apart.  It leads into the development section, which begins in C minor (on that key’s “dominant” harmony).
7:10 [m. 97]--Piano I, in octaves, begins a hushed, lamenting version of the main theme in C minor, accompanied by smooth harmonies in the middle range of Piano II, which also has the low bass notes.  After soaring to a high G, Piano I holds G-major and E-minor chords as the lower Piano II chords continue.  The left hand of Piano II, in octaves, plays two low three-note descents that create a continuous downward line and move the key a half-step lower, to B minor.
7:29 [m. 105]--Piano I, again doubled in octaves between the hands, plays the lamenting version of the main theme, now in B minor and harmonized in thirds. The Piano II accompaniment is barer here until Piano I abandons the harmonization in thirds.  Piano II then begins to play a harmonized descent in both hands, the right hand moving to the treble range.  Instead of soaring to a high F-sharp, as expected, Piano I leaps down twice, settling on a lower F-sharp.  The Piano II bass again plays the three-note descent in octaves.
7:43 [m. 111]--The expected second three-note descent from the Piano II bass follows, but not before Piano I begins to elaborate on its motion in thirds.  After the second low bass descent, Piano I continues this elaboration (adding sixths and fourths as well as thirds).  Then there are more low bass descents, and they now shift upward instead of continually moving down.  They alternate with the Piano I figures.  The right hand of Piano II, meanwhile, adds soft, punctuating harmonies on the weak beats.  The key of this atmospheric passage is B-flat minor.  After four alternations between the harmonies and low bass descents, Piano I expands its harmonies and soars high.  Piano II joins in a long, drawn-out cadence in B-flat minor.
8:14 [m. 123]--Very gently, both pianos begin a pattern of upbeats moving toward downbeats.  The left hand and right hand of each alternate.  The motion of these patterns is mostly either “dominant-to-tonic” or half-steps.  It becomes immediately clear that the top line of motion in Piano I is the disguised onset of a new, melancholy harmonized melody.  The upbeat-downbeat motion continues underneath it.  The passage begins in B-flat minor, touches on B-flat major, and then moves to D-flat major (“relative” to B-flat minor).  The right hand of Piano I plays three similar phrases of the new melody.  The right hand figures in Piano II echo the melody’s upbeat-downbeat gestures.
8:27 [m. 129]--As the melody reaches the end of its third phrase, the music builds in intensity and volume.  The melancholy phrases are abandoned.  Piano II introduces an anguished chromatic half-step on the upbeat-downbeat figure.  Piano I begins a two-voice imitation in its right hand, including more such piercing half-steps.  The right hand of Piano II, meanwhile, moves to intense tremolos in triplet rhythm.  The left hands continue their established patterns, but that of Piano I also begins to double the lower voice of the right hand imitations after two measures.  Brahms begins to notate D-flat as C-sharp, and it makes a “dominant” motion to F-sharp as a climax is approached.  At the climax, the upbeat-downbeat figures completely take over, and the patterns are similar to those at 0:39 and 4:10 [m. 17].
8:36 [m. 134]--The climax erupts into powerful chords and octaves in both pianos that work their way downward and move the music back to B-flat minor, the predominant key of the development section thus far.  The octaves suddenly emerge into material from Theme 2.  The left hand, then the right hand of Piano II play that theme’s jerky opening gesture as Piano I establishes the characteristic oscillating triplet motion in octaves.  The music rapidly diminishes, and Piano I’s right hand is left alone for a one-measure bridge.
8:42 [m. 138]--The left hand of Piano I maintains the oscillating half-step motion, but stretches it to broken octaves.  Piano II and the right hand of Piano I begin a mysterious variant of Theme 2 in B-flat minor.  They alternate and move in opposite directions.  The soaring line typical of Theme 2 is harmonized in both pianos, mostly in thirds, with the pianos still going in opposite directions.  There are dissonant chromatic notes forming “diminished” harmonies.  At the end of the phrase, these, along with descending octaves inserted within Piano II, move the music up a step to B minor, reversing the tonal pattern from the beginning of the development.  The entire Theme 2 variant is then repeated a half-step higher.
8:58 [m. 146]--With a sudden surge in C minor (another half-step higher), the opening figure of Theme 2 takes over and the left hand of Piano I stops its oscillation.  The hands of Piano II, in octaves, lead Piano I.  Piano II plays the characteristic figures with motion up and back down, and Piano I, in harmony, moves in the opposite direction.  This continues for two measures, after which Piano I begins to play breathless, leaping long-short rhythms that include chords.  Piano II, meanwhile, plays wide octaves, doubled between the hands two octaves apart.  There is then a huge crescendo and buildup on these patterns.
9:07 [m. 151]--Suddenly, a full statement of the first phrase from Theme 2 as heard at 1:15 and 4:47 [m. 35] is played in C minor, a half-step below its original presentation.  Here, the right hands of both pianos join in the main presentation of the “jerky” melody and upward rising line, with that of Piano II basically an octave lower and including the lower counterpoint.  The left hands join on the oscillating triplets, also an octave apart, lending them even more weight.  This is the climax of the development section, and in its last measure, it begins to dissipate and diminish in preparation for the re-transition.
9:16 [m. 155]--Re-transition.  Now hushed, the Theme 2 material is presented in imitation by Piano I in a three-voice texture.  The right hand of Piano II tentatively adds the half-step triplet figures and the left hand begins a pulsing “pedal point” on C, the “dominant” note of the home key.  The first phrase of imitation turns toward B-flat minor and major, but with the Piano II bass holding to the pulsing C.  The second phrase of imitation shifts up a step and moves back definitively to C minor, then C major.  A third phrase begins, following the sequence, beginning on C major.  Where the key shift would be expected, Piano I suddenly moves to dissonant (including “diminished”) harmonies and chromatic motion, sliding into F major/minor for the disguised and subtle arrival of Theme 1 for the recapitulation.
9:28 [m. 161]--The entry of Theme 1 in F minor is hidden by the continuing chromatic harmonies, which gradually move downward.  The “pedal point” continues.  The theme itself sneaks into the right hand of Piano II, but only the first gesture of it.  The chromatic, mysterious Piano I harmonies continue their descent.  The left hand of Piano II passes the pulsing C “pedal point” to the right hand.  The left hand then takes the continuation of Theme 1, which stalls, adding chromatic major-key inflections and syncopation.  Abandoning the effort, the left hand joins the right back on the pulsing C.  The Piano I harmonies suddenly lurch upward with half-step motion at the top.  The volume rapidly builds, and these short upward gestures lead into the passionate arpeggios and the more conventional continuation.
9:41 [m. 167]--The passionate arpeggios and violent chords erupt in an exhilarating way from their new lead-in material.  The parts are reversed from the exposition, with Piano II taking the arpeggios and Piano I the chords.  Except for this reversal and the new upbeat, they follow as at 0:15 and 3:46 [m. 5].  The reversal of roles of the two pianos from the exposition remains in force for most of the recapitulation.
9:53 [m. 174]--The version of Theme 1 with the heavy arpeggios follows, as at 0:28 and 3:59 [m. 12].  Again, the parts are reversed, with Piano 2 now taking the heavy arpeggios and Piano I the theme.
10:04 [m. 179]--The passionate outburst with stepwise descents and alternating arpeggios follows as at 0:39 and 4:10 [m. 17].  The parts continue to be reversed from the exposition.  Piano I has the stepwise descents in the right hand.
10:10 [m. 182]--The descending bass octave triplets, continuing arpeggios, and cadence gesture follow as at 0:44 and 4:16 [m. 20].  The parts continue to be reversed.  The descending triplets are in the bass of Piano I.  Brahms does reinforce the passage with an extra fortissimo marking.
10:16 [m. 185]--Transition.  With no mediation, the yearning melody from 0:51 and 4:22 [m. 23] is transposed from the previous F minor to B-flat minor, and the abrupt shift is striking.  The key change places it at a lower pitch level, changing its character.  It is in Piano II instead of Piano I, continuing the reversal.  The second measure of the melody has an altered contour, downward reach, and displacement down an octave.  Piano I is more active than its Piano II counterpart in the exposition, placing the alternation of the triplet rhythms and sighing figures between its two hands.  The left hand of Piano II, rather than taking these rhythms, adds a more solid bass support for the lower statement of the melody.  The smooth counterpoint to the melody is replaced by more straightforward harmonization.
10:25 [m. 189]--Transition to new key, analogous to 1:00 and 4:31 [m. 27].  The first phrase of the melody is played by Piano I, the continuation by Piano II.  The distribution of this continuation is otherwise altered.  The left hand of Piano II takes the urgently repeated triplet-rhythm chords, placing them in the same instrument as the melody.  Piano I has all of the sighing triplet leaps and low bass notes against them.  The buildup of the melody continues in Piano II, leading to the key change (to F-sharp minor, here already indicated at m. 192).  The oscillating triplet rhythms of the two-bar bridge are in the left hand of Piano I.
10:41 [m. 197]--Theme 2.  The choice of F-sharp minor for Theme 2 in the recapitulation rather than the home key of F minor is analogous to the exposition, where Theme 2 was not in the expected “dominant” key, but a half-step above it.  The pattern from 1:15 and 4:47 [m. 35] is followed, but re-scored, with the pianos again reversing roles from the exposition.  Both parts have thicker chords and added octaves.
10:50 [m. 201]--Analogous to 1:24 and 4:56 [m. 39].  The expressive phrase with triplets continues the reversal of parts, as does the restatement.  As expected, the restatement shifts up a half-step and turns to G major.  But after the first arpeggio, the left hand of Piano II inserts a disturbing repeated octave on F-sharp.  The second arpeggio moves back down to F-sharp instead of remaining on G.  But after this, the intrusive octave follows its sequence and moves down another half-step to F.  This prepares the motion back to the home key of F minor.
11:08 [m. 209]--Analogous to 1:42 and 5:15 [m. 47].  The first two measures establish F minor, the long-absent home key.  The opening part of the theme is replaced by a new, but similar passage.  In contrast to the jerky melody and its long-short rhythms, the passage is smooth and almost mysterious.  Both hands of Piano I and the right hand of Piano II play lines that follow the contour of the theme, and the left hand of Piano II adds a pulsating triplet-rhythm “pedal point,” not on F, but on its “dominant” note, C.  The expansion from the third measure returns to the original material, but the re-scoring here goes beyond simple reversal.  Piano I takes the soaring line, but its left hand drops out.  Piano II plays both the original harmonies from Piano I and the continuing triplet pulsation in the bass, now expanded to broken octaves.  The bass shifts briefly to F before the expected motion to E-flat.
11:17 [m. 213]--The continuation, analogous to 1:50 and 5:24 [m. 51], continues with some, but not complete reversal of parts from the exposition.  In this case, the right hand of Piano II takes over the rising line from Piano I.  The broken octaves in triplet rhythm, however, remain in the bass of Piano II.  The wide arpeggios originally in the right hand of Piano II are now doubled in octaves between the hands of Piano I, and include new upward arpeggios in the third and fourth measures.  The key touches this time on D-flat before the soaring line and full cadence in F minor.  The repetition of this soaring line and cadence is given to Piano I in octaves.  The right hand of Piano II has slightly urgent chords entering off the beat, but the pulsating broken octave triplets in its bass remain the propulsive force.
11:29 [m. 219]--Expressive phrase, arpeggios from Theme 1, and arching cadence, analogous to 2:02 and 5:36 [m. 57].  The reversal of scoring between the pianos continues.  This passage returns to an essentially direct reversal (albeit in the new key) after the variants in the preceding passages.
11:37 [m. 223]--Left hand (now Piano I) repetition of expressive phrase, analogous to 2:10 and 5:45 [m. 61], with brief motion to D-flat.  The scoring continues in direct reversal from the exposition, but the expanded cadence includes more octaves and begins the buildup earlier.  Brahms changes the key signature to F major here, earlier than the key change in the exposition.
11:46 [m. 227]--The variant of the expressive phrase, as well as the following buildup and cadence, are analogous to 2:19 and 5:54 [m. 65].  For the most part, the direct reversal of piano parts continues.  The rapid arpeggios in the first two measures are thinner, played only by the left hand of Piano I.  Its right hand adds a tolling C in the second measure.  Much of the rest is thicker than before, with fuller chords and added octave doubling.  In one measure (m. 232, corresponding to m. 70) where the two left hands had doubled the bass line before, it is played only by Piano I in octaves.
12:05 [m. 236]--Closing section.  Analogous to 2:38 and 6:13 [m. 74].  In the closing section, the role reversal of the piano parts is quite close (here there is an analogy to the quintet version, where there was also a direct reversal here between piano and strings).  The arching arpeggios are played by Piano II, as are the martial dotted rhythms.  Piano I holds long notes.  The descending echoes that were played by Piano II before are taken by Piano I.
12:14 [m. 240]--Analogous to 2:47 and 6:22 [m. 78].  The role reversal from the closing theme in the exposition continues.  Piano II plays the outward arching arpeggios again, reaching higher, along with the marching dotted rhythm.  The first echo is played by Piano I, and the extra second echo, the expansion, is played by Piano II.
12:25 [m. 245]--Analogous to 2:58 and 6:33 [m.83].  The harmonized descending groups of three-note patterns in straight rhythm, obscuring the bar line and building in volume, continue in an exact role reversal from the exposition.  Piano I plays the first group of three patterns, Piano II the second, and Piano I the third.  This third group is again not in the quintet version, so there is another extra measure here.  Thus, the two-piano version of the entire movement is two measures longer than the quintet version, with one measure added to each of these corresponding passages from the exposition and recapitulation.  The pianos join on the fourth passage, though still with reversed scoring from the exposition.
12:41 [m. 249]-Analogous to 3:07 and 6:42 [m. 87].  The lengthened three-note descents are now led by the right hand of Piano II.  The repetition an octave lower is thinned out by removing some harmonic notes.  There is no full F-major cadence here, as the weak-beat pulses that closed the exposition are omitted.  Instead of a cadence, the coda immediately begins with this material, building on the three-note descents.
12:45 [m. 253]--Part 1.  Piano II, in the tenor range with bass support, echoes its last descent.  From that point, an intricate web of imitation between the pianos follows on the three-note descents, with the top line of each gradually moving up by step and with Piano I following an octave above Piano II.  There is a steady buildup.  After three such exchanges, a climax is reached, the top lines stall on F and the imitative motion becomes more continuous, adding a downbeat before each descent.  The bass of Piano I establishes a “pedal point” with low octaves on F.  Three of these more continuous imitations then follow. 
12:58 [m. 259]--The Piano I answer to the third imitation is interrupted, and both pianos join together on a series of two-beat phrases, with Piano I taking the leading voice.  Its top line is more active than the harmonies underneath it.  The bass of Piano I rests on a very low F and plays slow, rising broken octaves.  The two-beat phrases steadily move down in the top voice of Piano I, and half-steps are again emphasized.  The tension steadily abates.  All voices except the bass reach the preparatory “dominant” harmony, slowing and diminishing in volume on a suspended, otherworldly oscillation.
13:09 [m. 263]--Part 2.  Brahms gives the tempo heading “Poco sostenuto.”  The right hand of Piano I leads a hushed meditation on the main theme, beginning with a descent from an upbeat instead of the usual ascent.  Piano II begins to imitate Piano I, but deviates quickly, adding characteristic syncopation.  The two right hands emerge into a contrary motion, with that of Piano I floating upward.  The bass in both left hands holds, then slowly moves on an unstable “dominant” harmony and “pedal point” F under this meditation in the right hands.
13:20 [m. 267]--The right hand of Piano II begins the meditation on the main theme anew, in B-flat instead of F.  The right hand of Piano I plays the syncopated “imitating” line previously played by that of Piano II.  The left hand of Piano I holds the harmonies.  The bass, especially in Piano II, remains on the “pedal point” F.  The statement is extended by two measures, lingering on the contrary motion, which changes direction and which the left hands join.  The left hand of Piano II inserts a descent to the low F.  The right hand of Piano I soars high.  Both pianos hold chords over a bar line, extending the statement by another measure.  They reach a delayed, unstable, incomplete, and chromatically-tinged cadence on B-flat.
13:36 [m. 274]--Both pianos play a series of syncopated chords held over strong beats and bar lines, continuing from the weak B-flat cadence.  The left hands of both instruments, leaving the bass range and playing in unison, emerge into syncopated Theme 1 material, and the music gradually moves back toward F minor, abandoning the major key.  After three measures, the right hand of Piano I leaps downward, coming to the level of the Piano II right hand.  After another measure, the left hands leap down two octaves back into the bass, and the pianos settle toward a “dominant” harmony as the volume reaches its quietest point.  The bass, doubled in both pianos, repeats its last gesture, which is clearly recognizable as the opening figure of Theme 1.  The right hands become detached on their off-beat chords.
13:57 [m. 281]--After the second bass arrival, the left hands lead a transition passage.  The descending line from Theme 1, beginning with an upbeat, takes over.  The left hand of Piano 1 moves an octave above that of Piano II.  After the bass lead-in, the pianos come together in unison with the hands an octave apart.  Brahms indicates a steady acceleration here.  This is accommodated by speeding up to a triplet rhythm.  The triplets begin to arch, working steadily upward and increasing in intensity and speed.  This leads directly into the main tempo and the passionate arpeggios, at which point Brahms finally changes the key signature back to the four flats of F minor.
14:06 [m. 285]--Part 3.  The passionate arpeggios from 0:15, 3:46, and 9:41 [m. 5 and m. 167] emerge in a “tragically triumphant” way from the buildup and acceleration.  The first two brief gestures are played as usual, with the pianos oriented as in the recapitulation (Piano II on the arpeggios, Piano I on the decisive chords) but the third, longer gesture is extended from three measures to four, with new harmonies focusing on major keys to the “flat” side of F minor (D-flat, G-flat, and C-flat).  The decisive chords in Piano I still use much half-step motion, although the heavy emphasis on major harmonies makes the passage more triumphant than tragic.  The fourth measure works decisively back to F minor.
14:18 [m. 292]--The arrival point is filled with feverish intensity.  Piano II moves from the fast arpeggios to a version of the slower ones that were heard under the second statement of the theme (which usually followed the fast arpeggios).  Piano I now takes the fast arpeggios, with both hands leaping down and back up between higher and lower registers (in the quintet version, these arpeggios were passed between string instruments).  The slower Piano II arpeggios move steadily downward to another big F-minor arrival.  The scoring of the three-measure pattern is then reversed, with outward octave expansion, in a second statement.  A third huge arrival on F minor follows as expected, with added heavy bass octaves in Piano I.
14:29 [m. 298]--Brahms suddenly applies the brakes with a sostenuto marking.  Piano II plays in unison octaves, returning to the slow arpeggios.  Piano I emerges from the last cadence into longer, heavy chords that leap back and forth, low to high.  Its bass emphasizes a low octave F.  The Piano II octaves are accented on strong beats, and the high chords of Piano I on weak ones, creating a sort of cross-rhythm.  The harmonies create an extended cadence on F minor, but not a typical one.  These last cadences focus on “plagal” or “subdominant” harmonies in an ending that foreshadows that of the Fourth Symphony’s first movement.  After two measures, Piano I plays three grand F-minor chords under the continuing slow Piano II arpeggios.  Piano II stops and joins Piano I on the last of these highly dramatic final chords.
14:48--END OF MOVEMENT [301 mm.]

2nd Movement:
Andante, un poco Adagio (Ternary form--ABA’). A-FLAT MAJOR, 3/4 time.
A Section
0:00 [m. 1]--Part 1.  The right hand of Piano II, playing espressivo and sotto voce in the tenor register, presents the main theme.  Its principal gesture, an upward skipping short-long rhythm that is followed, after the long note is sustained a beat, by a distinctive short-short-long pattern, remains almost constantly present.  The same is true for the harmonization in thirds or sixths.  Piano I, in octaves molto dolce, plays a halting accompaniment whose distinctive gestures include notes on the second halves of all three beats in the measure and the beginning of the second beat.  The left hand bass of Piano II plays together with Piano I, but reverses the direction of the gestures.  The first two measures are identical.  The third moves down toward the half-close, and the fourth establishes a cadence measure pattern by changing the short-long rhythm on the downbeat, in this case reversing it to long-short.  In the last two measures, the left hand of Piano I vacillates between following its own right hand or the bass of Piano II.
0:17 [m. 5]--The second phrase changes the contour of the short-short-long patterns after the downbeats, intensifying them.  The second measure of the phrase adds notes from the minor key.  The third and fourth measures blossom into a new arching approach to the half-close.  In the cadence measure, Piano I and the left hand of Piano II play only after the beats, without the added “halting” note on the second beat.  The left hand of Piano I mostly doubles that of Piano II an octave higher.
0:34 [m. 9]--Part 2.  The next phrase begins with the minor-key inflection, emphasizing it by omitting the short-long rhythm in the first measure.  The phrase intensifies in both volume and harmony, and moves strongly toward C minor (not the initially suggested A-flat minor).  Piano I introduces rich rolled chords, first on the off-beats, then on the downbeat in the last measure of the phrase.  This last measure actually reaches a half-close in C minor, emphasized by the first forte marking.
0:49 [m. 13]--At first, this phrase appears to back away and return to the opening phrase of Part 1, but the music already deviates and intensifies before the second measure.  As in the preceding phrase, the last measure reaches a new key, this time D-flat major, and with a strong full cadence rather than a weaker half-close.  Again, there are rich rolled chords in Piano I, now reaching higher.
1:05 [m. 17]--Part 2 of the A section concludes with an extended six-measure phrase.  As before, the beginning recedes back to the quiet level.  The first measures resemble the second phrase of Part 1, but without the change in contour of the short-short-long patterns.  The harmonic motion is even more adventurous here, but the volume remains quiet.  The A-flat-minor inflections are used to pivot to its related major key, C-flat.  The third measure adds a second skipping figure, and the fourth adds a very expressive turn at the half-close in C-flat.  The two-measure extension also emphasizes the skipping short-long figure, and quickly moves back home to A-flat major with a long-delayed full cadence.
1:31 [m. 23]--Part 3 (Codetta).  The greatly anticipated cadence is embellished with an expressive downward resolution (an appoggiatura).  This leads into the closing material.  It is extremely warm and beautiful.  The right hand of Piano II is still in the tenor range, still playing mostly in thirds and sixths.  The appoggiatura lends itself as a defining feature.  The left hand and Piano I play off the beat, the former in low octaves.  The last two measures of the first phrase accelerate slightly and add colorful chromatic inflections.  The bass in both pianos becomes more active.  Another yearning turn figure in Piano II, leading into a triplet rhythm, concludes the phrase and leads into the next one.
1:46 [m. 27]--The second phrase of the codetta begins like an intensification of the first.  The right hand of Piano I joins that of Piano II on the harmonized cadences and appoggiaturas.  The left hand of Piano I plays rolled fifths in the off-beat accompaniment patterns to compensate for the added strength, and that of Piano II moves to low bass octaves.  After the first two measures, there is intensification as before, but the colorful inflections are heightened and actually lead toward a new key.  The goal is the key of the B section, E major, notated as F-flat in this transitional passage.  Another triplet figure, now in Piano I, leads into the following transition.
2:02 [m. 31]--Transition.   At the climax, both pianos suddenly hold back in tempo and diminish in volume.  While Piano I emphasizes the lead-in to E major, Piano II slowly descends into that key.  Piano I plays octaves with some syncopation and internal harmonic motion.  Its bass leads up through half steps to B-natural, the “dominant” note in E major, and the four-sharp key signature is introduced.  Over the held Piano I bass B, chromatic descending thirds in the left hand of Piano II and a syncopated line in its right hand smoothly bridge into the theme of the B section.
B Section--E major
2:18 [m. 35]--The right hand of Piano I leads into the new theme with an upbeat on a rising octave.  It then continues on descending patterns in triplet rhythm.  Both left hands, meanwhile, play rolled chords against the melody, emphasizing the “dominant” note in the middle range.  The Piano I left hand moves to low bass B’s after two measures.  The theme is marked molto espressivo and is more intense than the A section melody.  After two measures, the right hand of Piano II enters and takes the lead with a continuation in straight rhythm, harmonized in sixths.  The unison triplets in Piano I continue underneath it as an accompaniment pattern.  The left hand of Piano II plays two more isolated rolled chords.
2:30 [m. 39]--The Piano II melody continues, harmonized in sixths, but it now turns to E minor.  The bass in both pianos adds rising octaves like the upbeats that led into the melody.  The now accompanying triplet rhythm in the Piano I right hand moves to the tenor range.  Piano II reaches a half-close in E minor.  At the half-close, Piano I plays a descending line in its left hand.  Its right hand joins, quickly moving back to E major and leading into the next statement of the melody.
2:42 [m. 43]--The right hand of Piano II provides the upbeat for a new, higher statement of the theme.  Its left hand adds a new counterpoint in clashing straight rhythm, bringing in the two-against-three conflict earlier than before, but vaguely imitating the right hand.  Piano I alone plays the rolled chords with both hands doubled an octave apart.  The continuation in straight rhythm is now played by Piano I, but unlike the beginning of the statement, the continuation is an octave lower than before.  Piano II continues the triplets in the accompanying role.  Its left hand continues its straight-rhythm line, now subordinate to both right hands.  The bass of Piano I solidly emphasizes the “dominant” note in octaves.
2:55 [m. 47]--The turn to minor is intensified.  It lands solidly on the “dominant” harmony right at the outset.  Piano II presses with the minor-key continuation in a more agitated manner.  Brahms indicates a steady, gradual acceleration.  Against this, Piano I plays two measures of pulsating triplets on B, the “dominant” note.  These triplets then pass to octaves in the right hand of Piano II in a role reversal, and Piano I extends the minor-key continuation.  After one more measure, it moves higher.  The Piano II octave triplets begin to move up and about, but circle back to the “dominant” B.  The extension, with a steady buildup, continues for three more measures.
3:08 [m. 53]--At the climax, Piano I suddenly and abruptly switches back to major.  The hands play in harmony an octave apart.  The Piano II triplets continue, as does the solid bass.  Piano I recedes in volume and tempo, settling back to a cadence in E major as the Piano II triplets dissipate.
3:20 [m. 55]--Epilogue.  Piano II plays chords, dolce, in the rhythm of the accompaniment to the main A section theme.  Piano I, in low bass octaves, plays an ascending octave upbeat in the dotted rhythm and character of the B section theme.  Its upbeats are then twice joined by higher right hand figures on descending ninths, the first using the chromatic note D-natural.  After four measures, the right hand moves to a new half-step pattern in the tenor range, using the dotted rhythm and another chromatic note, C-natural (which also appears in the Piano II chords).  This pattern, despite diminishing volume, has an urgent character obtained through a cross-rhythm (here a briefly implied 2/4 meter).  The left hand of Piano I plays low E’s, and Piano II makes one more arrival on E major.  On the last upbeat, the Piano I bass leaps down to D-natural (as had the right hand before).
3:42 [m. 61]--The key signature changes back to four flats.  Very quietly and mysteriously, Piano II again plays chords in the rhythm of the accompaniment to the A section theme.  Piano I again adds its dotted-rhythm upbeats, now mostly the urgent, dissonant leaping ninth.  Now the left hand descends and the right hand ascends, its leaps harmonized.  The right hand leaps resolve downward, easing the tension.  The harmony moves down by half-step from the previous E major.  The first two measures strongly suggest E-flat minor and major.  They are then shifted down another half-step for two measures that seem to fall in D minor and major.  Another half-step descent appears to begin, but it is immediately diverted back to D by the winding Piano I bass and the Piano II chords.  The right hand of Piano I drops out.
4:05 [m. 67]--The winding Piano II bass had included the note E-flat.  This note helps the D harmony to begin acting as a preparatory “dominant” leading to G minor, where Brahms now moves.  The note D is isolated in low Piano II bass notes along with a more active Piano I, which uses the familiar accompaniment rhythm of the A section.  The quiet, mysterious mood prevails.  After two measures, the Piano I right hand enters in thirds, dolce, with the opening gesture of the A section theme itself, not in G minor, but G major.  As the left hands persist on their repeated D’s, that opening gesture is repeated an octave lower in the right hand of Piano II, and now it is in G minor.
4:23 [m. 71]--The left hands move up a half-step to E-flat.  The Piano I right hand uses the G-minor harmony to pivot artfully to A-flat major, the home key of the movement.  The E-flat in the low bass becomes the “dominant” of A-flat, anticipating its full arrival.  The bass continue its established pattern on the new pitch.  The right hand of Piano I begins to spin out a yearning passage, harmonized in thirds, that is clearly targeted toward the arrival of the main A section theme in the home key.  After a brief acceleration and swelling of volume, the right hand of Piano II joins both hands of Piano I in a rich harmonization.  At that point, Piano I reaches its highest pitch, the harmony in both its hands expands to sixths, and then both speed and volume quickly recede, settling into the well-prepared, natural arrival.
A’ Section
4:38 [m. 75]--Part 1, as at the beginning.  The first phrase is played with no alterations.
4:55 [m. 79]--Second phrase, as at 0:17 [m. 5].
5:12 [m. 83]--Part 1, varied repetition.  The A’ section adds a second full and varied statement of Part 1 with “reversed” parts.  The first phrase transfers the main theme to Piano I, which maintains the original harmonies but adds an upper octave.  The accompaniment is given to Piano II, which adds a gentle rising arpeggio to each entry after the first beat of the measure.  Otherwise, it is similar to the original accompaniment, with some added chords.  In the last two measures of the phrase, the hands of Piano I are both harmonized in sixths and doubled an octave apart.
5:28 [m. 87]--The second phrase is similarly presented by Piano I.  The accompaniment in Piano II, which retains the decorative arpeggios, adds more chordal harmonies, including rolled chords at the end of the phrase.
5:45 [m. 91]--Part 2.  The varied repetition of Part 1 has extended the A’ section.  At this point, the analogous relationship returns, and this phrase corresponds to 0:34 [m. 9].  But it is really a continuation of the varied repetition, since Brahms retains the scoring of that repetition, with the melody in Piano I and accompaniment in Piano II.  Piano II, in fact, continues its established pattern of adding gentle arpeggios to each entry of the accompaniment rhythm.  The phrase builds, as it did before, moving to C minor, and Piano II continues to add richer chords to the accompaniment, rolling them at the climax.
6:01 [m. 95]--This phrase corresponds to 0:49 [m. 13], and like that phrase, it quickly intensifies and moves to a cadence in D-flat.  Both hands of Piano I play an octave apart, harmonized in thirds and later sixths.  Piano II continues its established accompaniment pattern with the initial arpeggios, and it adds even wider rolled chords at the strong arrival on D-flat.
6:16 [m. 99]--The six-measure phrase that concludes Part 2 is analogous to 1:05 [m. 17].  The half-close in C-flat and the full cadence in A-flat are retained.  Piano I continues to take the melodic lead, with the hands doubled an octave apart and each playing in two voices.  Piano II finally abandons the graceful ascending arpeggios at the beginning of its accompaniment patterns.  Rolled chords give way to block chords at the expressive turn figure in C-flat.  At the very satisfying cadence in A-flat, the last three melodic notes in Piano I (whose right hand is briefly independent) are doubled in speed from their previous presentation.  This causes the cadence to arrive on the last beat of the measure rather than the first.  The new coda that takes the place of Part 3 begins on the upbeat with this cadence.
6:43 [m. 105]--Part 3 (Coda).  The “codetta” is expanded to a full-scale coda, beginning with new material.  This new material is actually derived from the wide dotted-rhythm upbeat at the beginning of the B section theme, specifically as this upbeat appeared in the epilogue and re-transition.  The right hand of Piano I plays the first upbeat, a rising octave, and continues with this.  The left hand follows with descending ninths doubled in octaves.  Meanwhile, Piano II plays rising thirds in both hands, introducing some chromatic motion to match the chromatic leaps of a ninth in the Piano I bass.  Suddenly, the right hand of Piano II blossoms into joyously arching triplet octaves and a syncopated appoggiatura as the right hand of Piano I reaches upward.  Both pianos reach a broad climax here, then settle down.  Piano II again uses thirds in this descent.  The left hand of Piano I still plays in octaves but turns upward.
6:56 [m. 109]--The previous passage is played again with reversed parts.  The left hand of Piano II leads with the first upbeat octave while its right hand takes the descending ninths, now in high octaves.  Piano I plays the rising lines, the harmonies now spread out with both hands in octaves.  The joyously arching triplet octaves and syncopated appoggiatura are now taken by the right hand of Piano I.  Its left hand plays the more urgent bass octaves, which are harmonized by the left hand of Piano II.  This ending passage is suddenly expanded.  The closing gestures do not settle down, but increase in speed and urgency, repeating patterns with new chromatic inflections, especially in the right hand of Piano II, which remains very high, playing patterns beginning with falling and rising octaves, then with rising and falling half-steps.  This continues for three more measures.
7:15 [m. 115]--In the preceding passage, the presence of the note G-flat seemed to indicate a diversion to D-flat major.  Brahms thwarts that expectation with a sudden and striking detour to F major at the climax.  The right hand of Piano II leaps down in syncopated octaves against the rising bass of Piano I.  Octaves in the right hand of Piano I settle down from the climax.  They include syncopation on repeated notes..  Under them, Piano II leads through very active and colorful chords back to the home key of A-flat.  Everything rapidly becomes slower and quieter.  Piano I descends, again in syncopation, toward a cadence.
7:29 [m. 118]--At the cadence, the right hand of Piano I, in the tenor range, leads into the melody of the original codetta with the familiar appoggiatura.  Piano II plays chords on the off-beats under it, joined by octaves in the bass of Piano I.  Piano II then joins the melody at a higher level than Piano I, adding the familiar harmonization and leaving the off-beats to the bass of both pianos.  There is a rapid buildup.  Gloriously, the right hand of Piano I leaps upward, diverging from the original material and expanding the opening gestures with rich, full harmony and volume.  The right hand of Piano II subtly shifts to trail after Piano I on these gestures.  The bass, doubled in both pianos, plays compound broken octaves (two-octave leaps) on the keynote A-flat, signifying a final arrival.
7:46 [m. 122]--The codetta gestures are fragmented, with the right hand of Piano II still trailing that of Piano I.  Piano I then plays gentle undulations like slow trills and is trailed by the left hand of Piano II, which plays the undulations in the opposite direction.  It introduces the dissonant note a half-step above the “dominant,” reflecting a typical key relationship in the work.  Piano I comes to a close and the left hand of Piano II continues to trail, still including the dissonance.  Its right hand adds support.  The octaves in the bass of Piano I continue as the Piano II right hand, which plays in comforting thirds, leads to the last chord.  This quiet, sustained chord has the fifth or “dominant,” not the keynote, in the top voice of Piano I.
8:18--END OF MOVEMENT [126 mm.]

3rd Movement: Scherzo –  Allegro (Developmental Scherzo with Trio).  C MINOR, 6/8 and 2/4 time.
Part 1
0:00 [m. 1]--Theme 1 (6/8 time).  The scherzo begins ominously and extremely quietly with a thumping low C in the bass of Piano I.  After two measures, the three other hands enter on a highly syncopated unison arpeggio that seems to suggest A-flat major (the key of the slow movement) rather than C minor.  The left hand of Piano II does mark the downbeat.  After the arpeggio, Piano II slides into a sinuous melody, also syncopated and in unison octaves, that finally confirms the C-minor key.  The bass of Piano I continues to plunk the low C, keeping a steady beat.  The right hand of Piano I, in octaves and in a low tenor range, subtly enters with a response to the syncopated melody.  It is narrow and almost sinister, a quality enhanced by its syncopation.  After two identical gestures, it follows Piano II on arching lines, always syncopated, that reach high and close off the first statement of Theme 1.
0:11 [m. 13]--Theme 2 (2/4 time).  With the arrival on the “dominant” note G, Piano I drops out.  Piano II immediately changes the flowing 6/8 to an angular 2/4.  In unison octaves, Piano II utters a highly distinctive and rhythmic idea.  Still quiet and ominous, the percussive, driving force of this idea will later reach its full potential.  It begins with detached long-short rhythms on repeated G’s, then moves to a turn figure.  The second sequence reaches higher, changing the turn to a brief arpeggio.  In a third sequence, Piano I enters in support with staccato chords that remain close to G.  The bass of Piano II later joins these, leaving its right hand alone (in the lower octave) on the persistent long-short rhythm.
0:20 [m. 22]--Theme 3 (6/8 time).  After the hushed and ominous opening, both pianos suddenly break out into a loud and joyous chorale in C major.  It begins with an upbeat, in this case a half-measure after a rest on the downbeat.  It is richly harmonized and has a march-like quality.  The three-chord upbeats propel the chorale forward.  The first statement ends on the “dominant” harmony (after a brief detour to A minor) and is rounded off by repeated octave G’s in Piano I. 
0:27 [m. 30]--In the second statement, Piano II enters in firm octaves against the repeated G’s, its top voice an octave lower than that of the first statement.  A third octave doubling is added in the low bass.  Piano I follows a measure later and a third (plus an octave) higher.  In Piano I, the chords are doubled an octave apart between the hands, with both hands in the treble register.  Halfway through, Piano I abandons the imitation and simply supports the lower Piano II octave melody with chords.  Its top voice does not play the melody as it did before.  Again, octave G’s, now in Piano II, round off the statement.
0:34 [m. 39]--Re-transition.  The now-powerful syncopated arpeggios from Theme 1 (in Piano I) are combined with the thumping octave G’s that continue from Theme 3 (in Piano II).  These G’s also move down to C with harmonization on F-sharp.  There are two statements of the arpeggios with the thumping Theme 3 octaves.  The harmony remains closely tied to the “dominant,” but the syncopated arpeggios ensure that the key does not actually move there.  The two statements are bridged by octave G’s, and they also form another bridge to the reprise that opens Part 2.
Part 2
0:41 [m. 47]--Theme 1.  The theme begins as before, but without the two measures of introductory bass thumps, the octave G’s having taken care of that.  The bass of Piano II quietly enters, along with the syncopated arpeggio in Piano I octaves.  Continuing the reversal of parts, the right hand of Piano II enters with the “sinister” responses.  The second of these, however, reaches a step higher, as does the melody in Piano I.  The ensuing high syncopated arching lines build rapidly.  The hands of Piano I are now in octaves, both harmonized in sixths.  The right hand of Piano II follows, also in sixths.  The bass thumps (Piano II left hand) are now in low octaves.  The arching lines reach higher, and make a true motion to G.
0:50 [m. 57]--Theme 2.  The meter changes again to 2/4, and this time it remains in force for an extended passage.  Theme 2 is given again, but now fully in G minor (with an emphasis on its “dominant” note, D), played by both pianos an octave apart, and with a forceful, dramatic presentation as opposed to its secretive earlier statement.  It is also given in full harmony.  The top line of both pianos has the actual melody, including the turn figures and arpeggios.  The chords support the long-short rhythm.  The third, closing sequence is replaced by a repetition of the first two in a new key, B-flat minor.  Following this repetition, the pianos, still playing in long-short rhythms and arpeggios, cascade down and convert B-flat to the preparatory “dominant” in E-flat minor.
0:59 [m. 67]--An extended fugato (fugue passage) begins on the Theme 2 material, the first “developmental” passage in the scherzo.  It begins at a suddenly much quieter level.  The theme itself serves as a fugue “subject.”  It is first heard in the left hand of Piano I in E-flat minor, the central key of the fugue passage.  A “countersubject” is played against it in the bass of Piano II.  This detached line marches downward, leaps back up, and marches down again.
1:03 [m. 71]--The second fugue statement of the theme is in right hand of Piano II.  It slides from E-flat minor to B-flat minor.  The original marching, detached countersubject is in the left hand of Piano I, with some changes of contour.  The bass of Piano II, continuing from the first statement, adds a second “countersubject,”  It is a series of syncopated descents punctuated by detached low leaps of a fourth.  The “subject,” with its countersubjects, is extended by a measure to facilitate harmonic motion back to E-flat.
1:07 [m. 76]--The third statement is back in E-flat minor.  The theme is in the newly entering right hand of Piano I.  The original detached countersubject is in the right hand of Piano II, now at a much higher level, but the bass of Piano I adds a new line moving in contrary motion to the original line.  The second, syncopated countersubject is still in the left hand of Piano II, but it leaps up to the lower treble range.
1:10 [m. 80]--The fourth statement is again the B-flat-minor version.  The theme is again in the right hand of Piano II, an octave higher than the second statement.  The detached countersubject continues with another statement in the right hand of Piano I, and the syncopated one moves to the bass of Piano I.  The left hand of Piano II adds a new line in conjunction with the detached countersubject in the Piano I right hand (similar to that given the Piano I bass in the third statement).  This statement, unlike the second, is not extended by a measure.  Instead, the end of the last measure is slightly altered.
1:14 [m. 84]--For the fifth statement, Brahms does go back to E-flat minor, but changes the ending.  The theme is in the right hand of Piano I, at the same level as the first statement in its left hand.  The original detached countersubject is back in the left hand of Piano II, but it is now in the treble register.  The syncopated countersubject is high in the Piano II right hand.  That hand adds a second, lower voice playing the new line from the fourth statement that was in the Piano II left hand.  The left hand of Piano I adds new, isolated punctuations of the theme’s signature long-short rhythm, alternating with the same rhythm in the theme itself (in the same piano’s right hand).  The ending is altered to approach a different goal instead of B-flat minor.
1:18 [m. 88]--A sixth statement seems to begin with the theme in the right hand of Piano II, the detached countersubject in the bass of Piano I, the syncopated countersubject in the right hand of Piano I, and the “new” detached line in the Piano II bass.  But this is really the beginning of a large ascending sequence that serves as a transition.  It starts on D-flat, then briefly settles on the fugue’s main key, E-flat minor.  Elements of the two countersubjects alternate between hands of Piano I
1:21 [m. 92]--All fugue elements are fragmented and placed in close succession.  This transition is a type of fugal stretto (stacking of subject entries).  The syncopated countersubject and original countersubject are basically combined in both hands of Piano I and the left hand of Piano II, including harmonization.   The fragmented main theme is in the right hand of Piano II.  The thematic fragments work up to the secondary key, B-flat minor, and at that point the volume, which has been hushed throughout, suddenly and rapidly builds. The theme is fragmented even more urgently, reduced to a half-step.  A last shift to E-flat minor brings a sudden climax.
1:28 [m. 100]--At the climax, as the fugue breaks, Theme 2 is given its grandest statement yet, still in E-flat minor.  It is played in unison by both hands of Piano I and the left hand of Piano II.  It is the right hand of Piano II that intensifies it.  It plays octaves to “fill in” the gaps left in the long-short rhythms of the theme’s repeated notes, resulting in a heavily percussive effect.  It also briefly imitates the turn figures, also in octaves.  This passage is particularly effective in the two-piano version as opposed to the quintet.  This time, the third, closing sequence is also included, but at that point the unison playing breaks. The pianos play punctuating chords on each beat, the long-short “dotted” rhythm is relegated to the left hands, and the “filling” material in the Piano II right hand expands to full chords.  The closing phrase itself essentially follows the pattern of the first, hushed statement in Part 1, but is extended to the downbeat.
1:37 [m. 109]--Theme 3.  The 6/8 meter returns after a long absence.  The joyous chorale makes a welcome return.  It is given in E-flat major, the “relative” major key to C minor (as opposed to the home major key in Part 1).  Other than the key, the first statement essentially follows the pattern from 0:20 [m. 22].  Again, the statement ends on the “dominant” and is rounded off with pounding octave B-flats, now in Piano II.
1:44 [m. 117]--The second statement of the chorale in E-flat follows the pattern from 0:27 [m. 30] in the new key.  Piano II follows Piano I, a reversal from before.  Again, the statement is rounded off with punctuating octave B-flats, this time in Piano I.
1:51 [m. 126]--Re-transition.  The pattern from 0:34 [m. 39] is followed with the pianos reversing roles.  The thumping octaves are now on B-flat, moving down to E-flat with harmonization on A-natural.  The key center is still E-flat, with heavy emphasis on the “dominant,” B-flat.  As before, there are two statements of the syncopated arpeggios.  The bridging octave B-flats after the second statement move down a step, to A-flat.  Previously, they remained static.  This motion helps lead back to the home key of C minor and an extension of the re-transition.
1:59 [m. 134]--The volume suddenly recedes.  The thumping octaves move down again, to G.  This note is the preparatory “dominant” of C minor, and signifies an arrival there.  Piano II, still in unison octaves, plays an arpeggio in octaves on G.  Significantly, it is on the downbeats, momentarily interrupting the heavy syncopation.  But immediately, the volume builds again and the right hand forcefully shifts to the syncopated arpeggios in the high register.  The music now more closely matches the re-transition from 0:34 [m. 39], even in key, but the syncopated arpeggio is an octave higher than it was before.  The “bridging” octaves are back on their original pitch of G, but this time, the low, quiet Piano II arpeggio on the downbeat is added to them (it is played a total of three times).  As with the statements in E-flat, there are two statements of the syncopated arpeggios in C.
2:08 [m. 144]--A final statement of Theme 1 rounds off Part 2 of the Scherzo.  It is significantly different this time, not only due to its forceful presentation.  The syncopation is eliminated, and the unison arpeggio enters on the downbeat.  This shift had been prepared by the preceding low Piano II arpeggios on the downbeat.  Both pianos are in a powerful unison on this arpeggio.  It is faster, adding more notes in a long-short rhythm, and reaches up two octaves instead of one.  At the arrival of the melody’s continuation, Piano I takes the lead at a higher level than before.  It includes new parallel harmonies a sixth below, with the hands doubled an octave apart.  Instead of the original “sinister” line of counterpoint, Piano II supports the melody with almost joyously tolling, widely leaping octaves.
2:13 [m. 150]--At this point, the arching lines of the original Theme 1 melody are altered, with four measures being expanded to eight.  This is accomplished by adding a longer descending pattern and a second “wave” of motion that begins higher.  Piano I continues to play harmonies of sixths, then full chords doubled in both hands an octave apart.  The right hand of Piano II begins to play faster, downward-arching patterns while its left hand moves the octaves down to the low bass.  This extension facilitates an strong arrival on C instead of the “dominant” note G.  Each “wave” ends with a full, emphatic C-minor cadence.  The firm establishment of C minor is important, as it will be greatly undermined in the following coda.
Coda (Part 3)
2:20 [m. 158]--The coda returns to 2/4, and is almost entirely based on Theme 2, although the rising arpeggios from Theme 1 make an appearance at the end.  It begins with the last firm cadence on C minor.  Almost immediately, however, C seems to function as a “dominant” of F minor.  The frequent presence of the notes D-flat and E-natural, foreign to C minor, greatly undermine the key, and E-natural is sometimes used as part of a C major chord, including at the very end.  The version of Theme 2 from the climax at 1:28 [m. 100] is used, with both hands of Piano II and the Piano I left hand in unison, and the right hand octaves of Piano I “filling in” the gaps and adding brief imitation.  The first two measures follow the familiar pattern, seemingly in F minor, but then the long-short rhythms begin to move upward chromatically, touching on G minor and landing on A minor.
2:25 [m. 164]--A minor (more precisely, the “dominant” harmony in A minor on the note E-natural) is prolonged.  Fist, the turn figure is extended for more statements.  Then the long-short rhythm moves up again chromatically.  At this point, the “filling” octaves in the Piano I right hand add harmonies to create full chords, increasing the tension and excitement.  The rising long-short rhythms (also expanded to chords) actually do reach a full cadence on A minor, but it is immediately followed by a drop back down to the “dominant” note and a restatement of the pattern.  The chromatic ascent is subtly altered in its third measure, thwarting the A-minor cadence and diverting the music back toward C.
2:36 [m. 176]--The music arrives on C, but the chord is C major, not C minor.  The key is very ambiguous.  This arrival can either be interpreted as a “plagal” cadence in C minor (with the chord inflected to major by the so-called “picardy third”) or as a motion to the “dominant” in F minor.  Because of the strong downbeat emphasis of the C-major chord and the knowledge that C is the home key, F minor is weakened, although there was a cadence there (replacing the A-minor one) in the previous chromatic ascent.  The right hand of Piano I drops out, and the remaining hands play the opening of Theme 2.  The “filling” notes are given to the right hand of Piano II.  The presence of the note D-flat again suggests F minor.  Suddenly and unexpectedly, the right hand of Piano I enters with the syncopated arpeggio from Theme 1 as Theme 2 continues underneath it.  But the arpeggio is now fully harmonized and given in the context of 2/4 time, making the syncopation more “clipped.”  The bass notes are on the downbeat, softening the syncopation.  The harmonized arpeggio also prominently includes D-flat and suggests C major as a “dominant.”  The whole pattern is repeated.
2:43 [m. 184]--In the final phrase, Theme 2 continues to be hammered in Piano II octaves.  Piano I, meanwhile, plays leaping chords leading from an upbeat D-flat chord to a downbeat C-major chord.  This half-step motion down from D-flat to C is a modification of the “plagal” cadence and dominates the ending.  After three measures, Piano II stalls on the turn figure, which also heavily emphasizes the motion from D-flat to C.  Piano I plays a cascading chordal descent in the long-short rhythm, supported by true “plagal” motion (F to C) in its bass.  This descent also includes motion from D-flat major (or F minor) to C major.
2:48 [m. 190]--As the powerful Piano I descent reaches its last C-major chord, Piano II isolates the now almost violently insistent half-step motion from D-flat to C.  Downward octave leaps are added and, significantly, the note G, which helps to establish the finality of C (despite the highly disruptive D-flat).  Piano I plays two more C-major chords, sustaining the last one over the final defiant D-flat—C half-step.
TRIO (C major)
2:53 [m. 194]--Part 1.  The scherzo ends on the downbeat of m. 193.  The trio section begins immediately on the upbeat (second half) of that measure.  The meter changes to 6/8 before this upbeat.  The beginning of the trio section is indicated as m. 194 because in the total measure count, m. 193 is more properly assigned to the main scherzo section.  The upbeat itself is in the Piano I bass.  Piano II, in bass octaves, enters on the downbeat.  The Piano I bass establishes a solid foundation on low C and G, and the Piano II bass plays a constant rhythmic pattern on low C.  The Piano I pattern consists of two quick notes on the upbeats leading to a longer downbeat note.  After this brief preparation, the right hand of Piano I, also beginning halfway through the measure, begins to play a broad, noble, richly harmonized melody in the tenor range.  The theme prominently uses the “three-chord upbeats” that were typical of Theme 3 in the scherzo section.
3:02 [m. 202]--The melody, along with the bass, turns to emphasize the “dominant” harmony on G.  The Piano II bass pattern, while maintaining the same rhythm, becomes active and no longer fixed on a single note.  The same is true of the Piano I bass.  The top line of the melody becomes static, oscillating between long notes that move by step.  The three-note upbeats (largely harmonies in thirds) are in a middle voice.  After four measures, the harmony moves yet again to the remote B major, where it remains for another four measures.
3:10 [m. 210]--Part 1, varied repeat.  The introductory upbeat and downbeat are now preparatory “dominant” chords that move back to C major.  Piano I plays them with an octave leap, and Piano II adds harmony of a fifth to its rhythm against the chords.  The theme is played by Piano II in harmony, an octave higher than the previous Piano I statement.  Its left hand joins an octave below the right after a last statement of the rhythmic bass pattern.  Piano I accompanies with sonorous descending arpeggios and solid bass notes.  These remain anchored on C for three measures, then move away.
3:18 [m. 218]--Motion of the melody to G and B major, as in the previous statement.  Piano II has the long top notes, along with the three-note upbeats.  The bass of Piano I now takes the rhythmic upbeat/downbeat patterns.  The right hand of Piano I plays chords in the same rhythm that land on the second beat of each measure, alternating patterns with its left hand.
3:26 [m. 226]--Part 2.  The meter changes to 2/4, but the upbeat/downbeat patterns continue in the 6/8 motion (now notated as a triplet rhythm and shifting to the bass of Piano II).  It settles on G, the “dominant,” where it remains throughout the phrase, anchoring the unstable harmonies above.  In the 2/4 meter, the left hand of Piano I leads the right hand of Piano II in a long, mildly agitated series of detached notes.  The Piano II right hand follows at a close distance, but does not imitate the Piano I left hand; instead, the two hands play in contrary motion, with the Piano II right hand arching down and the Piano I left hand arching up.  The patterns steadily work upward and are highly chromatic, touching on ascending minor-key harmonies.  The Piano I right hand, in octaves, plays longer notes that also work upward.  These top patterns become steadily faster and higher.  At the high point, the pianos, with a high trill in the left hand of Piano I, arrive on a G-major chord.
3:33 [m. 234]--The phrase is repeated with the instrumentation rearranged.  The solid bass G’s in the upbeat/downbeat triplet rhythm are transferred to the Piano I bass.  The lines in octaves that begin with long notes and gradually become faster are transferred from the Piano I treble to the Piano II bass.  The Piano II right hand plays the original “leading” line with the detached notes, expanded to octaves and culminating in the high trill.  The original “following” line is now in the Piano I right hand.
3:41 [m. 242]--The main theme from Part 1 returns (along with its 6/8 meter) to round off the trio section.  The preparatory beats are played by Piano II, but its bass moves to the very unstable note B-flat.  The right hand sustains an octave C.  When the theme enters, it is played by Piano I in full harmony, and at the lower level of the original statement from the beginning rather than the higher presentation in the varied repeat.  The harmonies are consistent with previous statements of the theme, but the persistent B-flat in the Piano II bass, still in the familiar rhythm originally played by Piano II in the first statement, undermines the stability and creates great tension.  After four measures, it moves down through A to the more stable “dominant” note, G.  The long-held note in the right hand moves down to B-natural and A.
3:50 [m. 250]--The phrase from 3:02 [m. 202] and 3:18 [m. 218] is altered so that it settles at home on C major.  The long top notes are played by Piano I over block harmonies.  After touching on the somewhat dissonant note F-sharp, the Piano II bass works down to F and then arrives on the long-awaited low C.  Meanwhile, the melody itself arrives on C with a gentle cadence.  The three-note upbeats, first in octaves, then harmonized in thirds as before, are in the right hand of Piano II in the tenor register.  They are very chromatic, again emphasizing B-flat, and lend color to the C-major arrival.  The cadence in Piano I is reiterated twice, extending the phrase by a measure. 
3:59 [m. 258]--The phrase abruptly cuts off.  Piano I re-enters with three more C’s, but these are in the distinctive syncopated rhythm of the scherzo’s main theme, entering right before the downbeat.  They are preparatory for the rhythm in the return of the scherzo, to which they form a re-transition.  They are harmonized by the right hand of Piano II.  The bass of Piano I plunks low C’s on three straight downbeats, behind the displaced C’s in the right hand.  The Piano II bass, still on C, omits its last upbeat and isolates the final downbeat.  The syncopated C with this third downbeat (m. 261) omits its upper octave and has no harmony.  The low bass C’s provides a smooth transition into the scherzo reprise, which begins with more of them.
Part 1
4:04 [m. 1]--Theme 1 in 6/8 time, as at the beginning.
4:15 [m. 13]--Theme 2 in 2/4 time, as at 0:11.
4:24 [m. 22]--Theme 3 in 6/8 time, first phrase of chorale, as at 0:20.
4:31 [m. 30]--Second phrase of chorale with Piano I following Piano II, as at 0:27.
4:38 [m. 39]--Re-transition with arpeggios from Theme 1, as at 0:34.
Part 2
4:45 [m. 47]--Theme 1 with motion to G minor, as at 0:41.
4:54 [m. 57]--Forceful presentation of Theme 2 in G minor and B-flat minor, as at 0:50.
5:03 [m. 67]--Fugato in E-flat minor.  Theme in Piano I left hand and first countersubject in Piano II left hand, as at 0:59.
5:07 [m. 71]--Second statement.  Theme in Piano II right hand, first countersubject in Piano I left hand, new syncopated countersubject in Piano II bass, as at 1:03.
5:11 [m. 76]--Third statement.  Theme in Piano I right hand, first countersubject in Piano II right hand with new bass harmonization in Piano I left hand, syncopated countersubject in Piano II left hand, as at 1:07.
5:15 [m. 80]--Fourth statement.  Theme in Piano II right hand an octave higher, first countersubject in Piano I right hand, syncopated countersubject in Piano I bass, new line tied to first countersubject in Piano II left hand, as at 1:10.
5:18 [m. 84]--Fifth statement.  Theme in Piano I right hand, first countersubject in Piano II left hand in treble register, syncopated countersubject high in Piano II right hand harmonized by “new line” from last statement, and new punctuations in Piano I left hand, as at 1:14.
5:22 [m. 88]--Sixth statement and beginning of transition starting in D-flat.  Theme in Piano II right hand, countersubjects in alternation between hands of Piano I, “new line” in Piano II left hand, as at 1:18.
5:26 [m. 92]--Fragmentation and stretto of fugue elements leading to climax in E-flat minor, as at 1:21.
5:32 [m. 100]--Climactic statement of Theme 2 in E-flat minor with “filling” of gaps, as at 1:28.
5:41 [m. 109]--Theme 3 in E-flat major, as at 1:37.
5:48 [m. 117]--Second statement of Theme 3 chorale in E-flat, as at 1:44.
5:56 [m. 126]--Re-transition with Theme 1 arpeggios, then motion back toward C minor, as at 1:51.
6:03 [m. 134]--Extension of re-transition, including new non-syncopated Piano II arpeggios, as at 1:59.
6:12 [m. 144]--Exuberant final statement of Theme 1 without syncopation, as at 2:08.
6:17 [m. 150]--Expansion of Theme 1 melody and C-minor cadence, as at 2:13.
Coda (Part 3)
6:24 [m. 158]--Version of Theme 2 from climax, then chromatic upward motion to A minor, as at 2:20.
6:29 [m. 164]--Prolongation of A-minor material, as at 2:25.
6:40 [m. 176]--Arrival on C and tonal ambiguity.  Entry of arpeggios from Theme 1 in harmony, as at 2:36.
6:47 [m. 184]--Leaping chords and heavy emphasis on motion from D-flat to C, as at 2:43.
6:52 [m. 190]--Violently insistent motion from D-flat to C over final C-major chords, as at 2:48.
7:03--END OF MOVEMENT [261 (+193) mm.]

4th Movement: Finale – Poco sostenuto; Allegro non troppo; Presto, non troppo (Varied Sonata-Rondo [Binary] form, with introduction and extended coda). F MINOR, Cut time [2/2], 2/4, and 6/8 time.
INTRODUCTION – Poco sostenuto, Cut time [2/2]
0:00 [m. 1]--The left hand of Piano I begins the groping, mysterious introduction.  The opening is a series of rising octaves each leading to two rising half-steps.  The first begins on the home keynote F, leaping up an octave and then sliding up a half-step.  It is followed by other voices, each a fourth or a third away from the last one.  Each voice enters as the last one slides the half-step.  The left hand of Piano I is followed by its right hand, then the left and right hands of Piano II.  The second half-step comes after the previous note has been sustained (longer in the first voice, the Piano I left hand) and with the entry of yet another voice.  The right hand of Piano I is the exception.  It expands its second half-step into a melodic turn figure as the left hand begins another sequence an octave higher.
0:17 [m. 6]--The right hand of Piano I again follows the left, again in the higher octave, but at a different distance (a third instead of a fourth).  It is followed by the Piano II right hand, which is even higher, and the Piano II left hand at the previous level of its right hand.  The Piano I right hand again expands into a turn figure.  The notes following the rising octaves break the pattern somewhat.  The Piano II right hand rises a half-step, then a whole step.  The Piano II left hand moves down an half-step, then back up.  A third, abbreviated sequence follows as the Piano I right hand makes its turn.  The Piano I left hand begins a step lower, and the volume builds.
0:31 [m. 10]--The Piano I right hand follows its turn with another octave leap and then a simple downward half-step.  The Piano I left hand follows its half-step with a whole step, as the Piano II right hand had done before.  This is passed to the right hand, creating a new lower voice in that hand.  The Piano II right hand enters again, now dispensing with the rising octave and simply repeating the turn figure just heard in Piano I.  The Piano I right hand, in its new lower voice, then imitates the Piano II turn as both left hands enter.  The left hand of Piano II is an octave plus a minor third above that of Piano I.  The resulting harmony veers toward E minor, a half-step below the home key.  Both hands of Piano II leap upward on the E-minor chord.  Finally, the Piano I right hand, in its upper voice, repeats the first two notes of the turn figure.
0:42 [m. 13]--Suddenly, both pianos land on a loud dissonant chord.  The right hand of Piano II begins to pulsate in long quarter-note triplets, with the last note of one tied to the first one of the next, creating strong syncopation.  These notes are a “diminished seventh” chord, but combined with the bass, which holds the chord, then leaps down to a low octave C in Piano II, they form a “dominant” chord with a so-called added ninth, a very unstable sonority.  This chord restores F minor.  Against the low bass octave, the Piano I left hand leaps up to reinforce the Piano II harmony.  As the chords continue, both hands of Piano I, in treble octaves, ease into a new melodic line beginning with a long note, then winding downward.  The volume quickly diminishes, the builds again.  After three measures, the syncopated Piano II chords contract, then shift the harmony as the Piano I line concludes.
0:51 [m. 17]--The Piano I line in F minor concludes as Piano II violently changes the chord to the “dominant” chord in D-flat.  The pulsing begins again, but now the Piano II left hand leaps up and joins the right in the pulsations.  The Piano I bass sustains the low C.  After a measure, the right hand of Piano I joins the left hand of Piano II on the pulsations.  The Piano II right hand breaks from the pulsations and, in octaves, plays a descending D-flat-major line similar to that previously played by Piano I.  Its left hand takes the lower octave of this line after another measure, leaving the pulsations to the right hand of Piano I.  This passage again diminishes and builds.
0:59 [m. 21]--As the Piano II line concludes, a new sequence begins.  The pulsations move to the left hand of Piano I, then pass to that of Piano II.  The Piano I right hand plays another descending line, now in E-flat major (over its “dominant” chord) as the low bass (moving from Piano II to Piano I as the former takes the pulsations) becomes more active and rises by steps and thirds.  The Piano II right hand interrupts the Piano I line, and the harmony moves a level on the circle of fifths, to the “dominant” chord in A-flat.  The Piano I line continues.  In a role reversal, it then interrupts the Piano II line in the same manner.  At first, it seems that the harmony will move up the circle of fifths again, but it actually moves back to E-flat, now E-flat minor, as the bass reverses and descends by half-steps (the left hands again reversing roles).  The lines in the right hands continue in imitation for two statements.  At the very end of the sequence, the harmony lurches up a half-step to an E-minor chord.
1:14 [m. 29]--The left hand of Piano I leads back to the opening music.  It plays the rising octave on E, but now both right hands enter before it moves up.  They play the opening fragment of the “turn” figure harmonized by a descending octave (in Piano II).  They slide the music back home to F minor.  The Piano II bass enters with a rising octave on D-flat.  After the turn figure fragment, the Piano II right hand comes in against the bass with slow, syncopated chords.  At the same time, the Piano I right hand plays another descending octave against the chords.
1:27 [m. 33]--The right hand of Piano II begins the syncopated pulsations on slow triplets.  These are now a background for brief figures combining the rising octave/half-step and the turn.  The left hand of Piano I leads the right hand.  The left hand plays the rising octave/half-step while the right plays the turn fragment.  Piano II follows with its hands taking the same roles, the pulsations passing to Piano I.  The whole sequence is repeated, with a slightly more active turn fragment in both right hands.  When Piano I takes the pulsations for the second time, they are in the left hand, as the right is finishing its more active turn.
1:38 [m. 37]--The turn figure in the right hand of Piano II is expanded into a rising figure.  The pulsations, passing from Piano I to Piano II, are reduced in both thickness and activity.  They begin to leave off the first note of each triplet rhythm.  Piano I, in octaves, imitates the rising line.  The Piano II left hand has the bass.  The volume diminishes and everything thins out.  Piano II, in octaves at a lower level, plays one more rising half-step as the pulsations and bass move back to Piano I.  Both pianos then dissolve into isolated “dominant” chords together.  After the last isolated chord, a half-measure pause (m. 41) precedes the entry of the main theme at the beginning of the main “Allegro” section.
EXPOSITION – Allegro non troppo, 2/4 time
1:56 [m. 42]--Theme 1.  The exposition begins on an upbeat, or the second half of m. 41 (which is notated in 2/4 time).  The first full measure is m. 42.  The theme is broadly spun-out and has a sort of “leisurely intensity.”  Brahms even marks it tranquillo.  The lead role is given to Piano II, which begins on the upbeat and marches forth over a percussive accompaniment from Piano I.  Its right hand, in the tenor range, provides the driving, active impetus while the foundation in the bass consists of isolated, detached off-beat notes.  The first Piano II phrase establishes F minor and includes a brief trill in the second statement of the main gesture.  The left hand of Piano II does not play in this phrase.
2:02 [m. 46]--The next phrase moves toward C minor with a new left hand harmony in Piano II a third below the melody.  Both hands have distinctive upward-sliding grace notes.  In a third phrase, the lower left hand harmony drops out and Piano I stops its driving propulsion.  Both pianos, in arching lines (the Piano I bass in contrary motion), reach a full C-minor cadence with yet another brief trill in the melody.
2:13 [m. 54]--After the melody reaches the C-minor cadence, Piano II continues with a transitional phrase that moves back to F minor.  It uses the rhythm of the opening and is played in thirds.  The driving force now moves to the Piano I bass, which establishes a steady oscillation on a low C octave, supported by long Piano II left hand notes.  The Piano I right hand, still in the tenor range, answers Piano II with a similar gesture (also in thirds) that moves in the opposite direction.  The exchange is played twice.
2:18 [m. 58]--The theme begins again, now taken by the Piano I right hand in octaves.  The active accompaniment is now presented by Piano II, also in octaves.  The Piano I bass is slightly more active, moving away from the C.  The first phrase essentially follows the previous pattern with the exception that the melody adds a new upper note (an appoggiatura) in place of the trill during the second statement of the opening gesture.
2:24 [m. 62]--The second phrase begins as it had before, with the motion toward C minor.  There is, however, no lower parallel harmony in thirds.  Already in the second measure, Brahms introduces a surprise with a slide up a half-step, to D-flat, and a brief turn to major.  Piano I does play the brief trill here.  The third phrase with the arching lines continues in D-flat major with chromatic inflections.  This time the arching lines alternate between the top lines of the two pianos, starting with Piano I (both pianos provide harmony throughout).  Piano II’s statements are an octave lower.  When Piano I takes the arching lines a second time at a higher level, it diverts the cadence gesture back home to F minor (with the trill).  This cadence is reiterated by Piano II, thus extending the phrase.
2:38 [m. 72]--The transitional phrase is completely transformed into an epilogue.  It enters with the cadence again, but it surprisingly and sweetly changes from F minor to F major, and does not shift the key center.  The rhythm and contour are the same, and it is played in thirds and sixths.  As before, one piano answers another, but this time Piano I takes the lead.  The bass oscillation (which remains in Piano I) is on both C and F, giving the F-major key a strong confirmation.  The long notes are again in the Piano II left hand.  Piano II extends its answer on the second exchange, slowing and diminishing.  In a further extension, the Piano I bass slows down its oscillation to triplets while its right hand adds gradually dissolving harmonies.  For a moment, all is suspended on a half-close.
2:51 [m. 80]--Transition.  With sudden impetuousness, the transitional material begins with three upward steps in both pianos in octaves.  On the second, Piano I adds a third, higher octave, and on the third, the right hand of Piano I shoots up an octave while the Piano II bass moves down (creating a total of five octaves), all creating a sense of increasing force.  The step is clearly derived from the opening upbeat of the main theme.  The pianos burst into an intense series of upward gestures and scale runs, also derived from the main theme.  At first, the left hands are in contrary motion with the right hands, then Piano II follows Piano I in imitation.  Piano II is in low octaves, but Piano I adds harmonies.  There are three waves moving toward C minor, the third intensifying and extending the second.
3:01 [m. 89]--Piano I puts the brakes on the motion with four cadence gestures.  Meanwhile, the right hand of Piano II continues the propulsive material derived from the main theme.  The arrival on C minor seems to be confirmed (and this would be an expected key for the second theme), but after the fourth gesture, Piano I drops out and Piano II, suddenly quiet, has three rising fourths, each an octave higher than the last, that appear to move a level beyond C and strongly emphasize its “dominant,” G.  In fact, Piano II holds and sustains each G after the rising fourth lands on it.  Brahms places the marking “un pochettino più animato” (“a little more animated”) at this point.
3:08 [m. 94]--Theme 2: Part 1.  While Piano II holds its octave G’s, Piano I alone begins the lyrical, yearning theme.  It is highly chromatic and syncopated, with almost tortured lines.  The main argument in the top voice consists of a descending melody punctuated by small upward leaps in a clipped short-long rhythm.  The left hand plays a rising line against it.  The right hand of Piano II leaves the G to its left hand and adds another active harmony to the Piano I melody.  The key that was prepared in the transition, C minor, is undermined in favor of G, and the Piano I melody cadences there twice in a repeated pattern.  The descent is extended, and Piano I comes to a half-close in G minor as the right hand of Piano II drops out.  Then Piano II forcefully asserts itself again, repeating the pattern of rising fourths.
3:22 [m. 108]--A second statement of the theme appears to begin, with the Piano I left hand taking the lead and the right hand providing the rising counterpoint.  This is aborted after four measures.  The right hand of Piano II then starts the theme again a third higher, with the rising counterpoint in its bass.  Piano I provides internal harmony.  The Piano I left hand takes over the rising line from the Piano II bass after another four measures, exchanging it for slow cadence gestures.  There are two cadences in B major.  The extension moves yet again, now suggesting another major key, D.  In the extension, with the melody still in Piano II, the Piano I right hand provides the harmonies leading to an incomplete close, now in D.
3:39 [m. 125]--Part 2.  With a great outburst of passion, Piano I develops the cadence gestures from the end of the lyrical theme.  It passes these gestures between the hands.  Sometimes the gestures are faster, particularly in the left hand at the beginning.  Meanwhile Piano II begins a series of scale passages in both hands, sometimes with doubled thirds and always in triplets.  These are also passed between the hands, with changes of direction.  The triplet scales are passed to the Piano I right hand as well when it is not playing the cadence gestures.  The key finally moves decisively toward C minor.  After eight measures and two rising sequences, the shorter version of the cadence gesture takes over completely and is passed between the hands of Piano I with great intensification.  Piano II adds a solid bass in octaves here.
3:49 [m. 137]--In an enormous climax, the triplet scales completely take over in both pianos.  The right hand of Piano I, then the left hand of Piano II play cascading chromatic descents in octaves with syncopated rhythms that incorporate the triplet division.  The scales are passed among all four hands.  The right hand of Piano II suddenly becomes static, and the other hands add doubled notes and contrary motion, taking a brief detour to D-flat major.  C minor returns promptly, the Piano II right hand becomes active again, the pianos enter into an alternating dialogue, and two emphatic cadences in C minor, the first one incomplete, punctuate the motion.
4:00 [m. 149]--Both right hands expand the cadence with harmonized descending arpeggios and supporting chords in the syncopated triplet rhythm.  The left hands play rising scale fragments in triplets.  As the right hands twice approach another cadence (the second time more expansively), they briefly shift to the more decisive straight rhythm against continued triplets in the bass.  The second cadence is again extended with a rapid diminishing of volume and slowing of speed.  The bass, now in straight rhythm, is also active in this approach to the closing material.
4:11 [m. 161]--Closing section.  The music is suddenly restrained.  Both hands of Piano I and the right hand of Piano II play a dolce transformation of Theme 1, infusing it with a “Hungarian Dance” or “gypsy” flavor.  It includes distinctive sliding grace notes.  The Piano II bass plays a solid foundation on the downbeats, leaving the upbeats to the thematic fragments.  After six measures, the theme takes a smooth, expressive turn.  The entirety of this first statement remains in C minor.
4:23 [m. 169]--A second statement of the closing material begins.  It first six measures are a repetition, but then there is a slight alteration that brings it from C minor back to the home key of F minor.  Instead of the smooth, expressive turn, the upper voices continue the patterns with sliding grace notes.  The connection to the opening upbeat of Theme 1 becomes more explicit.  The upbeat figures then move to the original pitches from Theme 1.  After two statements there, Piano I drops out and passes the figure on to the right hand of Piano II, which plays it twice in rhythm, fading away.  Then a remarkable transition occurs.  Piano II slows the upbeat figure down to two full measures, with pauses between the notes and their harmonization.  This slowed down version becomes the actual upbeat to the reprise.
4:45 [m. 184]--Theme 1.  The first phrase is presented by Piano II with active Piano I accompaniment, largely as at 1:56 [m. 42] but without the upbeat, which occurred as a slowed-down version in the previous transitional passage.  The bass uses the same foundational notes, but it is shifted from off the beat to on the beat, and the upbeats have two notes.  Now it is also doubled in the left hand of BOTH pianos.
4:50 [m. 188]--The second phrase is harmonized in thirds, as at 2:02 [m. 46].  The Piano II left hand briefly abandons its doubling of the Piano I bass, but resumes it after two measures at a higher octave while still harmonizing the melody.  The third phrase has the same harmony and substance, but slightly different scoring.  Piano II leads on one arching figure, then Piano I, at a higher level, the second, and finally Piano II leads the third figure with the C-minor cadence.  Piano II had led on all these figures before.  The alternation resembles the statement of the phrase in D-flat from the passage at 2:24 [m. 62].  Also new, in keeping with this section, the bass is mostly doubled in both pianos and the harmony is generally richer.
5:01 [m. 196]--Development.  Here the music diverges from the exposition, beginning the long digression that takes the place of the development section.  Piano I overlaps and echoes the Piano II cadence, subtly altering the notes so that it arrives on a half-close in A-flat major (the “relative” key to the home key, F minor).  There then begins a series of exchanges between the two pianos based on the third, cadence phrase of Theme 1, all overlapping and at a quiet level.  Piano II begins, following the Piano I motion toward A-flat.  Piano I echoes Piano II again, and again makes a subtle shift, this time to a minor key, B-flat minor.  Piano II follows again, remaining in B-flat minor.  Finally, the last Piano I echo moves to D-flat major, which is the “relative” key of B-flat minor.
5:16 [m. 206]--Again overlapping with Piano I, Piano II confirms the motion to D-flat, a key where the music will linger.  Piano I, beginning with the left hand and following with the right, imitates this Piano II motion in the treble range.  Piano II continues to meander in D-flat major, and as Piano I enters in imitation, the volume builds.  With the two instruments essentially joining, the overlapping exchanges now cease.
5:25 [m. 212]--Beginning on the upbeat, and suddenly subdued again, Piano II, with the left hand of Piano I, begins to meditate on a prominent figure from Theme 1, its swaying motion now transformed into an almost lullaby-like version.  It is imitated and followed by both hands of Piano I (the left hand taking part in both sides of the alternation.  There are two such exchanges, still in D-flat major.  After the second exchange, Piano II slides down a half-step in harmony, to C major.  The two exchanges are repeated in that key at an even quieter, more mysterious level.  This time, the pianos are completely separate on the exchanges.  At the shift to C, each left hand subtly adds bass drones when the other piano is taking the lullaby figure.  The lullaby character prevails.
5:39 [m. 220]--Beginning a third series of paired exchanges, Piano II changes the direction of the upbeat, introducing a more subtle harmonic shift to F major (the major version of the home key), which Piano I, moving in the original direction, confirms in its first imitation.  The second Piano I imitation reaches a full, albeit brief, close in F major.  The left hands continue to alternate on drone bass octaves when not taking their turns at the exchanges.
5:45 [m. 224]--Re-transition.  The music gradually becomes animated, awakening from its lullaby-like trance.  The right hand of Piano I follows the other hands in another pair of harmonically unstable exchanges.  The harmonies follow both the leading lower voices and the following top voice.  The two exchanges build in intensity and rise in pitch.  One voice in the Piano II right hand sometimes doubles the top Piano I voice.  After the exchanges, the Piano I right hand continues to rise two more levels, and the lower voices revert to an accompanying role.
5:53 [m. 230]--A climax of pitch and volume is reached with the top voice in Piano I arriving at a dissonant high E-flat.  The Piano I right hand plays a series of short rising figures that gradually descend.  Piano II harmonizes and overlaps with them on falling figures harmonized in thirds, the hands an octave apart.  The Piano I left hand establishes a “dominant” pedal point on C.  This prepares another presumed arrival on F major or minor.  Over the course of eight measures, the pitch and volume levels of both pianos become lower as the pedal point C is held and reiterated.  At the end, the lower Piano II octave drops out and its bass joins the “pedal point.”  Everything is suspended on a half-close, with great expectation for a resolution to F.
6:04 [m. 238]--Reprise Resumed.  Transition, analogous to 2:51 [m. 80].  The arrival on F is thwarted, but only temporarily.  In a very elegant construction, Brahms resumes the reprise with the forceful original transition from the exposition.  The preceding development has taken the place of all the material from 2:13 [m. 54] through to the transition.  That material was primarily the restatement of the theme and a lullaby-like epilogue that ended a suspended half-close similar to the one here, a very neat parallel.  There, the transition began with the resolution on F, moving to C for Theme 2.  Here, Theme 2 must appear in the home key, so the original transition is played in B-flat minor (a key prepared in the “development”), which will lead to F in a delayed arrival.  This transition follows the pattern from the exposition quite closely, but after the forceful upward steps (which are themselves thinned out, the last gesture avoiding the lowest octave), the piano parts are reversed.  Piano II leads and is harmonized, while Piano I follows in octaves.
6:15 [m. 247]--Cadence gestures, with propulsive motion from the main theme now in Piano I, analogous to 3:01 [m. 89], but continuing the reversal of the piano parts.  The bass in Piano I does add low octaves, and the chords, now in Piano II, are doubled in octaves between the hands.  The arrival on F minor seems confirmed, then the rising fourths follow, now in Piano I.  Continuing the pattern of transposition, these rising fourths land on a sustained octave C, now the “dominant” note of the home key.
6:21 [m. 252]--Theme 2: Part 1.  Analogous to 3:08 [m. 94].  The theme’s outlines are the same.  It is presented in the new key (ostensibly the home key of F minor, but heavily emphasizing C minor, ironically the expected key in the exposition) at a higher pitch level.  The parts continue to be reversed from the exposition almost exactly.  Piano II plays the theme and the bass counterpoint while Piano I sustains the octave C’s and adds the higher counterpoint in its right hand.  The pattern of rising fourths follows as expected, again in Piano I.
6:35 [m. 266]--Analogous to 3:22 [m. 108].  Again, the previous pattern of the theme is followed except for the reversal of parts and slightly thicker scoring.  The reversal is very close in the first four measures with the “aborted” statement.  When the theme restarts a third higher (with the major-key cadences now in E), the parts are still basically reversed, but the main melody, in Piano I at this point, has octave doubling.  After two measures, the rising “bass” counterpoint is doubled for reinforcement in both left hands (rather than passed from one to the other), and the right hand of Piano II takes both voices of the previous Piano I part from the corresponding exposition passage.  The key suggested in the extension is now G instead of D.
6:52 [m. 283]--Part 2.  Analogous to 3:39 [m. 125].  The passionate material is now established in the home key of F minor.  For the most part, the pattern follows as expected, continuing with the reversal of parts from the exposition.  The cadence gestures, along with the rest of the Piano II part, are transposed higher than the Piano I part from the exposition, while the constant triplets, now in Piano I, are moved lower, creating a larger sonic space than in the exposition.  The second “faster” cadence gesture in the left hand of Piano II is omitted for practical reasons having to do with a leap down to a bass octave.  Throughout of the passage, some of the doubled thirds in the triplet figuration are converted into sixths and vice versa.
7:03 [m. 295]--Analogous to 3:49 [m. 137].  Enormous climax, as in the exposition.  The reversal of parts from the exposition continues, but the scoring becomes thicker, especially after the brief harmonic diversion (this time to G-flat), in the approach to the two huge cadences (now in F minor).  There, Piano II joins in two brief scale figures where Piano I had briefly paused before, resulting in even more intense activity.
7:13 [m. 307]--Analogous to 4:00 [m. 149].  The reversal of parts continues, but with some redistribution of the harmony, including the thinning to simple octaves in the syncopated descents, now in Piano II.  After the second cadence, the reversal of parts from the exposition breaks.  Piano I, in octaves, takes the straight-rhythm figures while Piano II plays the supporting chords.  Previously, the straight-rhythm figures were distributed to both pianos.  The second cadence itself is extended even more by an additional two bars beyond the F-minor arrival.  These prolong the retreat in volume and speed.  The active straight-rhythm bass stops in the second of these, leaving an isolated, detached upbeat “dominant” chord.
7:31 [m. 321]--Closing section.  It is analogous to 4:11 [m. 161], and follows the same harmonic pattern, but is radically different in character.  The dolce “Hungarian Dance” with its sliding grace notes is replaced by a tranquil, mysterious interlude.  The bass, played by Piano I, is low and ominous, and the right hand plays dark chords in the tenor register.  Piano II plays upbeat figures that seem like the ghosts of the formerly playful sliding grace notes.  Its left hand includes doubling of the Piano I right hand an octave lower.  The skeletal “melody” is audibly similar to the contours of the “Hungarian Dance,” retaining its prominent notes transposed to F minor.
7:43 [m. 329]--Analogous to 4:23 [m. 169].  As in the model, the first six measures of this second statement are a repetition.  After that, there is a harmonic divergence, as there was before.  But because the music is already in F minor, the motion away from there is a surprise.  It was already prepared in the sixth measure, where the melody and bass were inflected downward.  It is not the same motion as was heard in the corresponding passage, which would result in a move to B-flat minor.  Instead, in a concise, highly chromatic, and very mysterious seven-bar transition, the Piano II upbeats and the Piano I harmonies move decisively toward the key of C-sharp minor (notated in the transition as D-flat minor).  This key has already played a prominent role in the piece (having served for the second theme of the first movement).  The preparation is masterful, with a suspended, hushed approach and a slowing at the end.
CODA – Presto, non troppo, 6/8 time
8:12 [m. 342]--Section 1.  The change in tempo and meter is not as surprising as the change of key.  Brahms must now work his way back to F minor from C-sharp minor.  The “theme” of the coda is a 6/8 transformation of the movement’s main theme (Theme 1).  At first, it is presented in a hushed manner by Piano II alone.  The breathless pauses give it a distinctive character.  After four measures, the harmony briefly moves toward G-sharp minor.  After two more, Piano I enters with slower chords, the right hand of Piano II begins to oscillate, and the harmony shifts yet again, this time making a complete motion to B minor (through unusual “plagal” cadences), a whole step lower than the coda’s opening key.
8:18 [m. 350]--The previous pattern is repeated in B minor.  This time, Piano I adds light support to Piano II, which still leads.  The harmonic motion is the same.  It first hints at F-sharp minor, then fully moves to A minor.  The Piano I chords enter in their expected place.  At the end, the isolated oscillation is doubled in both hands of Piano II an octave apart, and the volume begins to build.
8:25 [m. 358]--The pattern appears to begin again in A minor, but the Piano I chords are now present from the outset and the low bass is not.  Piano II plays the main melodic line in octaves.  There is a powerful and steady crescendo.  After three measures, Piano II breaks away from the pattern, reaching higher.  The continuing “plagal” cadences in Piano I first suggest E minor, then C major.  Piano II adds another higher octave to the right hand.  The C-major harmony begins to function as the preparatory “dominant” to F, the ultimate goal.  The crucial note B-flat is introduced as Piano II begins an extended buildup on the familiar oscillation.  The Piano I chords hover on C major and G minor, harmonies that suggest F major.  At the top of the buildup, though, the note D-flat signals an arrival on F minor, and the C harmony becomes an explicit “dominant.”
8:33 [m. 368]--The tension is released by a suddenly cascading unison scale in both hands of both pianos, stretched over three octaves with the lowest doubled in the left hands.  It finally confirms F minor.  The scale leads directly into a powerful version of the coda “theme” in the home key.  Piano I plays it, harmonized in thirds with the hands doubled an octave apart.  Piano II adds a thundering foundation that almost seems to imitate the timpani playing the home and “dominant” keynotes.  The original pattern is followed at first, including the expected hint at C minor.
8:42 [m. 378]--There is an unexpected bump a half-step to D-flat on the oscillation.  The oscillation itself gradually climbs upward, supported by the continuing timpani-like bass, now in both pianos doubled in octaves.  The right hand of Piano II takes over the doubling of the Piano I right hand on the thirds.  When this steady upward climb reaches its high point, the bass has established a “pedal point” on the “dominant” note C, nearly making a full motion there.  In the last measure, the Piano I left hand breaks away from the “timpani” figures and adds solid chords in the middle register.
8:47 [m. 384]--Another forceful arrival is marked by a cascading scale, this one adding chromatic notes to F minor.  The right hands of both pianos play it in unison octaves.  The left hands continue with the timpani-like bass.  The scale breaks in the right hands after three measures.  Now the left hands (starting with just that of Piano I) continue the downward motion of the scale, still with the added chromatic notes and some octave doubling.  The right hands make strong gestures derived from the “timpani” figures that seem to point toward an arrival.  After three more measures, the right hand of Piano I moves up in octaves against the descending scale in the left hands, and the right hand of Piano II adds supporting chords.  Both pianos then come to an extremely emphatic cadence in F minor with two punctuating chords on weak beats.  In fact, by adding one last downbeat chord, Brahms could easily have ended the movement at this point.
8:56 [m. 394]--Section 2.  What might be called the coda’s huge “extension” begins here.  Instead of a downbeat chord to end things, Brahms remains on the weak beat and makes a motion toward the “dominant” on a slur to the downbeat.  On the next weak beat, he seems to begin this again, but, led by the right hand of Piano I in high octaves, a totally unexpected and forceful statement of the opening material from Theme 2, the lyrical, yearning chromatic melody, begins.  The cadences are on F, not C, and F is presumably still in force as the home key.  This clarifies the  key ambiguities in the earlier statements of the melody.  The left hand of Piano I and the right hand of Piano II provide harmonic support and counterpoint.  The bass, in low octaves of the Piano II left hand, has the familiar rising line against the Theme 2 melody.
9:05 [m. 404]--The Theme 2 material leads into an exciting sequence of chords.  The right hand of Piano I plays these chords while its bass holds long notes.  Piano II propels the 6/8 motion with continuous neighbor-note figures in octaves.  The sequence moves upward in waves.  The first two, over bass pedal points on the “dominant” notes (C and D-flat) of F minor and F-sharp/G-flat major, have a longer downward motion.  The third “wave” consists of two almost identical units emphasizing B major and minor.  The fourth is similar to the third, but emphasizes C major and minor.  This leads back home to F minor with a fifth “wave.”  This is similar to the first two, but is more emphatic.  The Piano I bass and both hands of Piano II (abandoning the running motion) join the hammered, detached chords.
9:21 [m. 424]--In a tour de force, the “coda” theme and the Theme 2 melody are combined.  The left hands play a variant of the former in octaves.  The right hands play the latter in unison.  This is presented in four “waves.”  The second is a fourth higher than the first, with new harmony (thirds and sixths) in the left hand of Piano I and both right hands.  The third is at the same basic pitch level as the first, but the melody is an octave higher.  Full chords are introduced in the right hands.  There is a great buildup in volume and agitation.  The fourth “wave” is a half-step lower than the second, but in the higher octave.  The full chords are spread out between the right hands, and the left hand of Piano I introduces the harmony in thirds again.  It arrives at the remote key of B major.
9:33 [m. 440]--Suddenly, all becomes quiet.  The B-major arrival is brief, and the harmony effortlessly slides up to C.  Piano II plays a harmonized version of the Theme 2 melody.  Piano I, in harmonies of thirds and sixths, plays fragments of the “coda” theme marked dolce.  The harmony quickly shifts from C major up to G major, where it briefly lingers.
9:39 [m. 446]--The Theme 2 melody moves back to Piano I.  The Piano II right hand moves to the tenor range and plays the “coda” theme harmonized in thirds.  The Piano II bass begins to establish a very extended “pedal point” low C, which is quickly passed to Piano I and then shared by both left hands.  The harmonization of the “coda” theme in Piano II expands to sixths and is split between the hands.  The Theme 2 material in the Piano I also settles on C as the “dominant” not of F minor, but of F major.  After eight measures, it expands upward, then fragments and isolates its distinctive downward leaps.  The music begins to die away, turning toward minor at the end of another eight measures.
9:54 [m. 462]--The hands of Piano II subtly separate, and the left hand moves away from the long C “pedal point.”  It plays widely arching arpeggios against the continuing “coda” theme figures in the right hand.  Piano I plays the downward leaps over low bass octaves.  There is a mixture of F minor and F major here.  The bass in both pianos settles on a highly anticipatory “dominant” preparation, with the “leading tone” at the bottom.  The right hand figures in Piano II are reduced to three rising notes harmonized in thirds.  The Piano I right hand departs from its unison notes and octaves and pauses on a third from the “dominant” chord.  In addition to fading away, the music also slows as it fragments, pausing on a tension-filled fermata.
10:04 [m. 467]--The run-up to the close is an extended pattern of syncopation that steadily builds in volume and intensity.  After the fermata, Piano I quietly enters first.  The right hand plays a chromatic descent off and in anticipation of the beat.  The left hand keeps the actual beat with detached notes, mostly two-note harmonies or octave leaps.  Piano II follows a measure later and a fifth higher in quasi-imitation of the syncopated pattern in the right hand, its left hand supporting that of Piano I.  Piano I begins the pattern an octave higher.  Piano II also repeats its pattern an octave higher with fuller harmony.  In the third round, Piano I leaps another octave, adding lower octaves and other harmonies, mostly thirds.  Piano II follows, only a fifth higher, but with the same expanded harmony.  The patterns now include downward leaps.  Piano I has two more, Piano II only one, each beginning a third higher than the last and starting with an octave leap.  The syncopated chords become thicker and louder as the pianos come together.
10:11 [m. 478]--Now loud and very agitated, the right hands continue their syncopated chords, Piano I an octave above Piano II.  The left hands play octaves on the beats, following the syncopated chords.  After four measures, the octaves in the left hands (doubled an octave apart) take over the syncopated off-beat entries and the thick right hand chords (with Piano II now moving above Piano I) are on the beats.  The pattern is less regular.  There are still chromatic descents, but these become shorter, often only two chords, and they reach higher.  The leaps between the patterns become wider until, at the end, there are huge leaps of an octave and more as the right hands switch position four more times.  Finally, the chords stop.  Piano I, doubled in three octaves, plays the final, highly distinctive gesture, beginning on a two-note upbeat.  This rises up three notes, then turns to a plunging descent, ending with the bottom three notes of the F-minor scale.  These three notes mirror the opening of the coda in C-sharp minor, which started with the bottom three notes of that scale, albeit harmonized.  Piano II punctuates this final gesture with chords and low octaves on the two downbeats.
10:35--END OF MOVEMENT [492 mm.]