Third Movement: Rondo pastorale, D major, 2/4 time

The third movement is written in sonata-rondo form. It begins with a martial rhythm in the piano, but immediately, the "pastorale" character is presented through the theme played by the flute and the rustic pedal point (such as a bagpipe drone) played by the piano. However, it unexpectedly comes to a half cadence on the dominant (with a fermata) of the parallel minor, B minor, abruptly shifting to an overture-like style imbued with Mozartian humor. This interruption using a fermata is a rhetorical device known as abruptio. This involves placing silence within a texture where it is not expected. Of course, improvisational ornamentation is possible here, but by emphasizing the interruption of the flow, the sudden change in the subsequent musical idea—namely, the contrast between the pastoral character and the urban, theatrical character—is highlighted. This theme is repeated multiple times, but at the fermatas, piano fioritura is notated thereafter.

Incidentally, the flute theme (a1) is an anagram of the famous contrapuntal theme (the "Do-Re-Fa-Mi" sequence developed by Mozart in his Symphony No. 41 in C major, "Jupiter," K. 551) that is later developed (in solfège: [Sol-] Re-Fa-Mi-Do = [A-] E-G-F#-D). This pastoral theme transforms into the aforementioned humorous character and is taken over by the piano. Even in the transition to the second theme, a figure similar to the "Jupiter" motif is emphasized with syncopation (measures 33-34, D-C#-G-F#, in solfège: Do-Ti-Fa-Mi). This motif was frequently used in Mozart's symphonies and masses. It was itself derived from Gregorian chant and was widely known in the 18th century as the opening of the hymn Lucis creator. Furthermore, it is a commonplace figure in Fuxian counterpoint, which Mozart studied and used to teach his own pupils, appearing in the works of dozens of composers from Palestrina to Brahms. Hummel himself used it in a piano piece (the third movement of his Piano Sonata, Op. 20) prior to this sonata.

The second theme in the dominant key, in contrast to the preceding theme, is composed of fluent, virtuosic figures consisting of scales and arpeggios, and its flow is uninterrupted. The piano and flute play arpeggios and scales in a concertante manner.

In the development section, Fux's theme appears in G major. The harmonic progression after the Do-Re-Fa-Mi motif in G major is very similar to the first theme of the fourth movement of Mozart's Symphony No. 41 in C major, "Jupiter," K. 551, and can be seen as an homage to his mentor, Mozart. This theme modulates progressively through E-flat major, F major, and G minor.

After the Jupiter motif is presented four times through two phrases (c1, c2), the development through motivic elaboration begins from measure 113. The developing flute motif is both a variation of the Jupiter motif and, considering its melodic contour (descending leap ⇒ ascending stepwise motion), can also be regarded as an expanded form of the first theme, thus situating the "Jupiter" motif within a consistent context from the exposition.

In the recapitulation, the first theme once again contrasts its pastoral and buffa characters; in the latter, the flute accompanies the piano with repeated notes. In the subsequent transition, the allusion to the "Jupiter" motif heard in the exposition is no longer present. This is likely because it was sufficiently developed in the development section. Maintaining the brilliant character of the second theme, the climax of the movement is led, and after repeated perfect cadences are postponed, building anticipation, the coda finally enters at measure 185.

The coda, after recalling the first theme supported by a rustic drone, concludes brilliantly with the cheerful musical idea characteristic of a'.

How to Read the Formal Diagram

This formal diagram is read from left to right for each row, and from top to bottom, following row 1, row 2, and so on. Due to the structure of the piece, common elements are aligned vertically, allowing for an immediate understanding of where each motif appears. The roles of the numbers and other elements in each row are as follows:

• First row: Section name
• Second row: Measure numbers
• Third row: Motif and its measure numbers
• Fourth row: Key
• Fifth row: Cadence (ped indicates dominant pedal point)

The '!' at the bottom outside the box indicates points where the music intentionally deviates from the listener's expectation, such as a disrupted cadence.