The first movement is in the concerto variant of sonata form. The main theme is introduced with a horn solo, with the piano interceding. The woodwind instruments proceed to introduce a small motif (borrowed, perhaps unconsciously, from the opening of the first movement of his Serenade #2) before an unusually placed cadenza appears. The full orchestra repeats the theme and introduces more motifs in the orchestral exposition. The piano and orchestra work together to develop these themes in the piano exposition before the key changes to F minor (from F major, the dominant) and the piano plays a powerful and difficult section before the next orchestral tutti appears. The development, like many such sections in the Classical period, works its way from the dominant key back to the tonic while heavily developing themes. At the beginning of the recapitulation, the theme is replayed before a differing transition is heard, returning to the music heard in the piano exposition (this time in B-flat major / B-flat minor). A coda appears after the minor key section, finishing off this movement.
This scherzo is in the key of D minor and is in ternary form. Contrary to Brahms's "tiny wisp of a scherzo" remark, it is a tumultuous movement. The piano and orchestra introduce the theme and develop it before a quiet section intervenes. Soon afterwards the piano and orchestra launch into a stormy development of the theme before coming to the central episode (in D major). The central episode is brisk and begins with the full orchestra before yet another quiet section intervenes; then the piano is integrated into the orchestral effect to repeat the theme of the central episode. The beginning section returns but is highly varied.
The slow movement is in the tonic key of B-flat major and is unusual in utilizing an extensive cello solo within a piano concerto. Brahms subsequently rewrote the cello's theme and changed it into a song, Immer leiser wird mein Schlummer ("My Slumber Grows Ever More Peaceful") with lyrics by Hermann Van Lingg. (Op. 105, No. 2). Within the concerto, the cello plays the theme for the first three minutes, before the piano comes in. However, the gentler melodic piece that the piano plays soon gives way to a stormy theme in B-flat minor. When the storm subsides, still in the minor key, the piano plays a transitional motif that leads to the key of G-flat major, before the cello comes in to reprise, in the wrong key, and knowing that it has to get back to B-flat major, the piano and the orchestra make a transition to finish off the theme in its original home key of B-flat major. After the piano plays the transitional motifs, the piano quickly reprises the middle section in a major key, before playing the final chords to end this beautiful movement.
The last movement consists of five clearly distinguishable sections, of which the last is a 'stretto' (faster) coda. The first section (bars 1 to 64) is built on two themes: the first and main theme of classical structure (1-8) is first played by the piano and then repeated by the orchestra. The second theme (16-20) is likewise presented by the piano and repeated - and expanded - by the orchestra. A kind of development of the first theme leads to the next section. The second section (65-164) is built on three themes. Number three (65-73, a minor) is very different from the previous ones: by its minor key and its rhythm, which is Hungarian, in Number four (81-88) is still in a minor and number five (97-104) in F major. These three themes are repeated several times, which gives the section the character of a development. The third section (165-308) can be seen as a reprise of the first; it is built on the first two themes, but a striking new element is given in 201-205 and repeated in 238-241. The fourth section (309-376) gives the themes 3, 5 and 4, in that order. The coda is built on the main theme, but even here (398) Brahms presents a new element, restating the main theme in triple rhythm (a device he used earlier to end his violin concerto) over a little march, first played by the piano, then answered by the orchestra, which trades themes with the soloist before the final chords.