General Overview

Regarding Schubert's autograph materials related to this work, an autograph draft remains, bearing the inscription "April 1818." Two points are particularly noteworthy in this autograph score, which includes two unfinished movements:

• First, the point where composition was interrupted. In his unfinished works, Schubert generally tended to stop composing at the end of formal sections, specifically often interrupting composition at the end of the development section or the beginning of the recapitulation. In contrast, in the first movement of this piece, despite there still being space on the lower part of the same staff paper, the pen was laid down unresolved on a dominant seventh chord on B in the middle of the development section.
• Second, the tempo marking is missing in the other movement, which is separate from the opening movement, making it impossible to determine whether it is a middle movement or a final movement. However, the form and texture of this movement suggest those of a final movement, and in Schubert scholarship to date, it is generally considered to be a final movement rather than a middle movement.

There is also a view that the Adagio in E major, D 612, complements this sonata as its slow movement. The fact that this Adagio D 612 was composed in April 1818, the same month as this sonata; that the theme of the Adagio resembles the theme of the first movement's development section (from m. 87); and that the E major of the Adagio is the key to which the dominant seventh chord on B, where the first movement's composition was interrupted, resolves—all seem to indicate a close relationship between the two. On the other hand, the fact that the autograph score of the Adagio bears a title, composition date, and the composer's signature, and that Schubert did not have the habit of inscribing these in the middle movements of his sonatas, negates the possibility that the two were conceived as a single sonata. Furthermore, watermark analysis of the paper used in the autograph scores indicates that the paper used for Adagio D 612 and Sonata D 613, while similar, is not identical, thus providing no definitive evidence for either theory.

It should be noted that this work is treated as an unnumbered appendix in the Bärenreiter edition based on the New Schubert Edition, while it is assigned the number 11 in the Vienna Urtext Edition edited by Martino Tirimo.

Movement-by-Movement Analysis

First Movement: Moderato, C major, 3/4 time

It adopts sonata form but features a structure typical of Schubert's later works, where a mediant key is inserted between the tonic and dominant regions, thereby reducing the tension of the exposition (for details, refer to the analysis of Piano Sonata No. 21, D 960).

The first theme begins quietly in C major, and the 12-bar theme is varied twice (from m. 14, from m. 25). The first theme group moves towards a dominant seventh chord on D, the dominant of the dominant (m. 39), anticipating a second theme in the dominant key, but in fact, the second theme is presented in E-flat major (m. 41). Led by the dominant seventh chord on D that reappears in m. 62, a third theme emerges in G major from m. 68. However, this theme deviates into E minor, so the establishment of G major is postponed until the section from m. 78, which can be called a coda.

The development section begins in A-flat major (m. 87) and, like the third theme, consists of a decorative accompaniment of sixteenth notes and a melody of long note values. After modulating through F minor to D-flat major, the opening motive of the third theme is repeatedly used (m. 102). After returning to A-flat major via F minor, the composition breaks off unresolved in the midst of modulation at m. 121.

Second Movement: No tempo marking, C major, 6/8 time

As mentioned above, the autograph draft lacks a tempo marking, but an Allegretto would be expected from the dynamic 6/8 time. This movement also broadly adopts a sonata form similar to the first movement.

The first theme group is in C major. After an 8-bar theme, a melody in E minor appears like a middle section, showing a typical Schubertian interplay between major and minor (m. 14). The opening theme returns in the tonic key, closing the first theme group. The fact that the first theme group takes a ternary form is closer to the form of a middle movement or the rondo form of a final movement than to the sonata form of the opening movement.

Following the first theme group, a fanfare-like passage in C minor resounds powerfully (m. 32). This passage is repeated in E-flat major (m. 36), and after a transition, it arrives at A-flat, which is reinterpreted enharmonically as G-sharp, and the second theme group is presented in E major (m. 47). After this gentle second theme continues for a while, G major is hinted at (m. 68), with C major (m. 65) serving as a pivot. After a perfect cadence, a third theme, also serving as a coda, appears in G major, closing the exposition. This structure, where a mediant key is inserted between the opening theme and the theme concluding the exposition, is similar to that of the first movement.

The development section begins in E-flat major. After a section in D-flat major (m. 105), G major appears in m. 121, foreshadowing the recapitulation in C major. In the autograph score, the left-hand notation ceases from m. 126, and the composition breaks off after the first note of m. 134, which is G (considered to be the first note of the recapitulation), is written.