General Overview

This work is the last of the six piano sonatas Schubert began composing in 1817 while staying at the Schober family's residence. While the autograph manuscript is dated "August 1817," two copies of the completed sonata bear the date "August 1818." If these are not misprints, it is believed that Schubert conceived this work in 1817 and completed its fair copy approximately one year later during his stay in Zseliz, where he was employed as a music teacher for the Hungarian nobleman Count Esterházy. At the autograph manuscript stage, the work had an unconventional movement order, placing the Scherzo as the second movement and the slow movement as the third. However, in the two copies, the order of these two middle movements is reversed, resulting in the standard movement order.

Furthermore, due to differences in the treatment of fragmentary works composed particularly during his middle period, this sonata is assigned different numbering: No. 10 in the Vienna Urtext Edition edited by Martino Tirimo, and No. 9 in the Bärenreiter Edition based on the New Schubert Edition.

Movement-by-Movement Analysis

Movement 1: Allegro ma non troppo, B major, 4/4 time

This movement, while adopting the framework of sonata form, reveals an attempt to expand it through modulations and the introduction of multiple themes.

At the opening, the tonic triad of B major is presented in unison as an arpeggio, and in measure 3, a dominant seventh chord of C-sharp minor suddenly appears. When this theme is presented again, it deviates to C major after a general pause, and a new theme is introduced in G major (m. 15). This second theme, in contrast to the staccato first theme, is played legato and flowing. The second theme transitions to E major in its last three measures, and a gentle third theme is presented in E major (m. 30). Up to this point, the key progression moves downwards by thirds: B major – G major – E major. This third theme transitions to F-sharp major, and in measure 42, a fourth theme appears, closing the exposition in F-sharp major. Thus, while the exposition broadly follows sonata form by beginning with a theme in B major and closing with a theme in the dominant, it is noteworthy that two additional thematic areas are inserted in between. Later in his career, Schubert was known for breaking the tonic-dominant tension typical of conventional sonata form by inserting a single third-related key area between the tonic and dominant in the exposition (for details, refer to Piano Sonata No. 21, D 960). This very characteristic can be observed in the sonata form of this movement.

The development section is divided into two parts. The first half, by repeating the motif of the first theme, modulates through third-related keys from B minor to D major, F major, and A-flat major. Then, after passing through E-flat major, the latter half, derived from the second theme, appears in B major. The return of the tonic key in the latter half of the development section, without waiting for the recapitulation, is a rare occurrence in conventional sonata form, but there is a reason for this. In this movement, as already attempted in Piano Sonatas No. 2 D 279, No. 3 D 459, and No. 4 D 537, the recapitulation appears in the subdominant key of E major. Maintaining the key relationships from the exposition, the second theme is then recapitulated in C major, the third theme in A major, and the fourth theme returns in the tonic B major, bringing the movement to a close.

Movement 2: Andante, E major, 3/4 time

Broadly, the movement adopts an ABA' form, with the A section itself taking a compound ternary form of aba'.

The A section consists of three parts, aba', with a quiet 'a' section in E major enclosing a modulating and intensifying 'b' section.

In contrast to the static A section, the B section creates contrast through the consistent use of sixteenth notes. It has a tonal structure that begins in E minor and modulates to C major. At the end of the B section (m. 46), the chromatic progression that characterized the opening of the B section's theme is brought to the foreground, preparing for the recapitulation of the A section.

In measure 52, the opening theme returns, marking the recapitulation of A. Here, staccato chromatic sixteenth notes are incorporated into the inner voices, integrating elements of the main section and the middle section. In the recapitulated a' section, creative touches beyond mere restatement are observed, such as starting in the third-related key of G major (m. 70) or briefly introducing minor keys (m. 80). Notably, G major also serves to foreshadow the following third movement.

Movement 3: Scherzo: Allegretto, G major, 3/4 time

It consists of a Main Section (ABA') – Trio Section (CDC') – and a Da Capo of the Main Section. Both the Main Section and the Trio Section adopt the typical ternary form for a Scherzo movement.

The humor characteristic of a Scherzo movement is evident in points such as the dotted quarter note, which should be emphasized on the strong beat, beginning unaccented due to being placed in the middle of a slur, and the opening section, which progresses in 4-measure units, concluding after 10 measures, two measures short of a full phrase. From measure 11, both hands proceed in a canonic fashion, and then together, with a crescendo, they lead to a diminished seventh chord that resolves into a general pause without proper resolution (m. 19). The A section then concludes in the dominant key of D major (m. 28).

The B section begins in the third-related key of B-flat major and proceeds in a canonic style. By reinterpreting B-flat as A-sharp and inserting a general pause that leaves it suspended on a half cadence in G major, it prepares for the recapitulation of the A section. The A' section is a recapitulation of the A section, but harmonic adjustments have been made to allow it to close in the tonic key.

 The Trio section is in D major and consists of a combination of a folk-music-like half note + quarter note rhythm and a continuously flowing eighth note rhythm. Following an 8-measure C section and an equally 8-measure D section, the C section returns for only 4 measures, an octave higher.

Movement 4: Allegro giusto, B major, 3/8 time

This movement, with its two thematic areas presented a fifth apart and both returning in the tonic key, can broadly be interpreted as a sonata form without a development section. However, in reality, since the first thematic area itself is in ternary form, it would be more appropriate to interpret it as ABA'B', a form closer to that of a slow movement rather than a sonata form.

The A section, a B-major passage based on quarter notes + eighth notes reminiscent of the fourth movement of Beethoven's Piano Sonata No. 15, encloses a light, staccato middle section in D major.

The B section begins in F-sharp major and is played dolce and softly (m. 51). F-sharp minor section is inserted (m. 67), or sudden shifts between major and minor keys (m. 81) are typical characteristics of later Schubert. After a light theme is presented in G major (m. 133), a transition (m. 173) leads to the return of the A section in the tonic key (A' section, m. 195).

By concluding the A' section in E major, the subsequent B' section returns in the tonic key of B major (m. 255). Amidst the gathering clouds created by the interplay of major and minor keys, the movement concludes with a fortissimo B-major triad.