Second exposition: The piano enters with an ascending scale motif. The structure of the exposition in the piano solo is similar to that of the orchestral exposition.
Development: The piano enters, playing similar scales used in the beginning of the second exposition, this time in D major rather than C minor. The music is generally quiet.
Recapitulation: The orchestra restates the theme in fortissimo, with the wind instruments responding by building up a minor ninth chord as in the exposition. For the return of the second subject, Beethoven modulates to the tonic major, C major. A dark transition to the cadenza occurs, immediately switching from C major to C minor.
Cadenza: Beethoven wrote one cadenza for this movement. The cadenza Beethoven wrote is at times stormy and ends on a series of trills that calm down to pianissimo. Many other composers and pianists have written alternative cadenzas.
Coda: Beethoven subverts the expectation of a return to the tonic at the end of the cadenza by prolonging the final trill and eventually arriving on a dominant seventh. The piano plays a series of arpeggios before the music settles into the home key of C minor. Then the music intensifies before a full tutti occurs, followed by the piano playing descending arpeggios, the ascending scale from the second exposition, and finally a resolute ending on C.
The second movement is in the key of E major, in this context a key relatively remote from the concerto’s opening key of C minor (another example being Brahms’s first symphony.). If the movement adhered to traditional form, its key would be E-flat major (the relative key) or A-flat major (the submediant key). The movement opens with the solo piano and the opening is marked with detailed pedalling instructions.
III. Rondo – Allegro
The finale is in sonata rondo form. The movement begins in C minor with an agitated theme played only by the piano. The movement ends with a C major coda marked presto.
“I saw almost nothing but empty pages; at the most, on one page or another a few Egyptian hieroglyphs wholly unintelligible to me were scribbled down to serve as clues for him; for he played nearly all the solo part from memory since, as was so often the case, he had not had time to set it all down on paper.”