First Movement

The first movement, in sonata form, adopts an extremely simple structure. The form of the exposition is largely conventional, except for its modulation to the parallel key of the dominant after a half cadence in the dominant, its circumvention of many keys, and the secondary theme beginning in a minor key rather than a major key. The development section is also short, at 26 measures, and consists of a phrase from the codetta in its first half, and a sequence of phrases including the first two measures of the movement in its second half. When the sequence reaches the tonic key, it directly initiates the recapitulation.

In this movement, the transitions between stillness and motion provide overall contrast. For example, in the principal theme group, a dynamic theme consisting of a turn motive and an ascending leap is followed by a more lyrical theme centered on stepwise motion. Between the rapid, continuous descending scales of the transition section and the lively secondary theme characterized by perpetual motion rhythms and syncopation in the accompaniment, a long, contrapuntal phrase sequence is interspersed. In the closing theme, a two-note pedal point imparts a leisurely character, forming a strong contrast with the codetta, which possesses high tension due to its rhythm, staccato embellishing notes derived from the secondary theme, and ascending leading-tone motion in the high register.

Slow Movement

The slow movement has a graceful character, contrasting with the lively first movement. In this movement, all themes are repeated with the leading instrument alternating, seemingly exploring the expressive possibilities of combining the two instruments. For instance, the four measures of the minor theme (mm. 17~) show no significant changes in voice leading, but due to changes in voice allocation and the presence or absence of instruments, there are four variations in the exposition alone. In the recapitulation, the repeated G becomes a trill, and it is repeated in yet another new form. Furthermore, the double stops and arpeggiated chords in the accompaniment of the E major theme (mm. 67~) enrich the sound compared to their previous appearances.

Final Movement

The final movement is in rondo form. The thematic figure, which traverses a fixed range, recalls the turn motive of the first movement. In addition to the perpetual motion rhythm of the sixteenth notes, the constantly shifting relationship between the two instruments—including voice exchange, inversion, parallel motion, and motivic echoes—likely contributes to the music's fluidity.

The opening theme is constructed from common figures: arpeggios and scales, which dominate the entire movement. Additionally, the ascending melodic figure with ornamentation (m. 5) is transformed and included in episodes (e.g., mm. 57~, 117~). While this limitation of material unifies the entire movement, the diversity of keys during theme recapitulations (C major, B major, E-flat major) and changes in accompaniment figures prevent redundancy. Furthermore, the interest in the Neapolitan key observed in Nos. 1 and 2 is also evident in the modulation to the Neapolitan of the dominant, E-flat major, in the coda.