(Third Movement) F-sharp minor, 6/8 time

An Adagio movement that maximally exploits the structural characteristics of the instrument, allowing for smooth transitions across the keyboard. F-sharp minor is the enharmonic equivalent of G-flat minor, which is a third below the tonic key, thus demonstrating tonal construction based on a third relationship here as well.

The harmonic opening theme in F-sharp minor constructs a long musical idea, avoiding simple repetition, and making it difficult to identify the motives that constitute the theme. This is followed by a second theme, played over fragmented chords and a syncopated rhythmic inner voice. Then, a third theme appears, shifting to D major, where characteristic rhythmic motives of the tonic and dominant are repeated above and below a figure that seems to ornament two continuously sustained notes.

The music returns to F-sharp minor, but the opening theme retains only its harmonic progression in the bass voice, while the upper voices are elaborately ornamented. This reveals that the 'characteristic lack of motivic features' was indeed a defining trait of the opening theme. The second theme is recapitulated in D major, and the third theme in F-sharp major.

The third theme appears again, this time in G major, followed by a partial return of the opening theme, concluding in F-sharp major.

Although some analyses discuss this movement as being in sonata form, the absence of motivic development techniques for the themes, coupled with the movement's fantasia-like character, seems to defy 'listening for form' in this movement. If one were to formally categorize it, it might be considered, for instance, a large two-part form with three themes.