(Third Movement) 2/4 time, F minor, Sonata Form

Exposition

Following the previous movement, it is introduced by a series of repeated dotted rhythms on diminished seventh chords. The main theme shares its initial note on the downbeat with the main theme of the first movement, and its repetition over a Neapolitan II chord also parallels that of the first movement's main theme. It might even be said that the entire work is derived from the main theme of the first movement.

The secondary theme appears in the dominant key of C minor, and it too is characterized by a Neapolitan II chord.

Development and Recapitulation

In this sonata, the structure from the development section onwards is repeated by means of a repeat sign.

The development section is written exclusively in B-flat minor. After the main theme is treated developmentally, a new motive with rhythmic characteristics appears. The main theme is then treated again in F minor, and a dominant pedal (C) fully prepares the tonic key.

In the recapitulation, both the main theme and the secondary theme are restated in F minor, and a repeat sign leads back to the beginning of the development section.

Coda

Rather than a coda functioning as a "second development section" like in the first movement, it strongly features elements that develop instrumentally and conclude the piece brilliantly. It becomes Presto, closing the entire work with passages of repeated chords and the main theme supported by arpeggiated harmonic patterns.

In contrast to the developmental sonata form of the first movement, the third movement appears to strongly emphasize the classical two-part sonata structure, with the key relationships of the two themes in the exposition (tonic → dominant) and the key relationships of the development and recapitulation (subdominant → tonic) being symmetrically constructed.

Originally, the development section in sonata form was a transitional process, a transitional section, leading towards the return to the tonic in the recapitulation, in contrast to the tonic → dominant relationship of the exposition. Therefore, transitional passages unrelated to the themes of the exposition were often inserted. However, the insertion of motives with thematic characteristics, as seen in the third movement's development section of this sonata, cannot be discussed within the framework of traditional sonata form.

The compositional method of expanding the first movement's coda as a "second development section" and the appearance of new motives in the third movement's development section all relate to the structure of Symphony No. 3 "Eroica," Op. 55.

In this work, Beethoven can be said to have taken a new step in the genre of the piano sonata by fusing the wide dynamic range and register obtained from the Érard piano with symphonic developmental techniques and compositional methods.