Allegro ma non troppo, B-flat major, 2/4 time

This movement adopts the rondo-sonata form, which integrates elements of both rondo and sonata forms.

The movement opens with a sustained G in octaves. Following this, the opening theme (a) emerges from the dominant chord of C minor, modulating to B-flat major within eight measures. When the theme is repeated an octave higher (a), a new motive (b) briefly appears in E-flat major. This concludes on G, after which the opening theme returns (a). At measure 42, motive b reappears, this time shifting to A-flat major. The return of motive a in the tonic key closes the opening section. Thus, this section is structured by the alternation of two motives, corresponding to the refrain (Rondo form) and the first theme (Sonata form exposition).

In this movement, changes in rhythmic patterns coincide with formal divisions. When a new theme is presented at measure 86, the accompanying figure also transforms into dynamic sixteenth notes. This theme corresponds to the couplet in rondo form and the second theme group in sonata form. Initially presented in F major, it is extended into two parts, as a section in F minor follows, separated by a general pause (measures 154–155).

At measure 224, the same G as the opening resonates, and the opening theme returns in the tonic key. While this section corresponds to the rondo refrain in terms of the return of the opening theme, it also serves the role of the development section in sonata form, as a developmental section utilizing material from motive b commences at measure 256, following the aab motive sequence as in the opening.

Signaled by the return of the opening G at measure 312, the opening theme returns in the tonic key (refrain / first theme of the recapitulation). Like the opening, it consists of two motives, but appears here in a shortened form. From measure 360, the couplet / second theme group returns in the tonic key, B-flat major. Here too, the initially presented two-part structure is maintained, with the latter part recapitulated in B-flat minor.

Led by the G in octaves, which resonates again at measure 490, the opening theme returns fragmentarily. After a general pause, the movement concludes with a rushing Presto coda in B-flat major.