First Movement: C minor, 4/4 time, Sonata Form

It begins decisively with the main theme, played in a three-octave unison arpeggio of the tonic chord. Following a transition passage (m. 9–) with a chromatically descending inner voice, it reaches the relative major, E-flat major, where the subordinate theme appears (m. 23–), ornamented by turn figures and modified by chromatic alterations. Subsequently, another subordinate theme emerges in a dialogue-like manner between the upper and lower voices. This leads to a transition passage featuring numerous chromatic passages and motives from the main theme. While the first half (exposition) would typically close in the key of the subordinate theme, in this sonata, it remains open, ending on a dominant ninth chord of the tonic key.

This open ending of the first half serves as a connection, on one hand, to the beginning via a repeat sign, and on the other hand, to the second half (development). The second half (m. 75–) begins with the main theme in C major, followed by the first subordinate theme (m. 79–) and the main theme (m. 83–) in F minor. The main theme then modulates through G minor and C minor, accompanied by eighth-note triplets, leading to a dominant ninth chord, similar to the end of the first half, and pausing on a dominant seventh chord. At measure 99, marked by a long fermata, it would have been possible to insert an Eingang according to the performance practice of the time.

After the recapitulation of the main theme (m. 100–), the recapitulation of the first subordinate theme is omitted, and motives from the main theme are developed polyphonically (m. 118–). The second subordinate theme is then recapitulated in the tonic key (m. 131–). Furthermore, a coda based on the main theme is provided (m. 168–), closing the movement pianissimo.