II. Adagio-Gary Graffman

Adagio in A-flat major, A–B–A–B–A form. Nostalgic in its traditional classical character (one of the few instrumental adagios Schubert wrote), the opening theme of this movement is an elegant, touching melody that eventually undergoes remarkable tonal and cadential treatment, undermining the peaceful setting. Charles Fisk has pointed out that the voice-leading of the first phrase, 1–7–1–2–3–4–3, is based on the initial A-flat digression in the beginning of the Allegro.[21] The unorthodox, chromatic harmonic structure of this movement is generated from a short progression that appears towards the end of the A section,[21] leading to a plagal cadence in the subdominant key (D-flat), chromatically colored with its own minor subdominant chord (G-flat minor). The importance of this progression and of D-flat in general is emphasized by its quotation in a climax of the finale's exposition. This diversion of the main theme's expected cadence leads to the haunted atmosphere of the B section, which is full of chromatic modulations and startling sforzandos. In the second appearance of the A and B sections, almost the entire music is shifted a semitone up, further cementing the importance of the ascending minor 2nd in the sonata as a whole. The focal plagal progression returns transformed at the end of the movement, with even subtler chromatic coloration and more distant modulations, touching on C major, before the piece finally ends in the tonic, the theme now weakened and given an illusory quality due to the evasion of cadences, free modulation, and tendency toward digression into troubled minor passages.