Schubert: Piano Sonata No.21, D.960

Introduction

Franz Schubert's last three piano sonatas, D 958, 959 and 960, are the composer's last major compositions for the piano. They were written during the last months of his life, between the spring and autumn of 1828, but were not published until about ten years after his death, in 1838–39.

Sonata in B-flat major, D. 960

I. Molto moderato. This movement employs a three-key exposition. The first theme introduces a G-flat trill that anticipates the following harmonic events – a shift to G-flat major in the central section of the main theme, and, after a return to the tonic, an enharmonic shift to F-sharp minor at the start of the second theme. After a colorful harmonic excursion, the third tonal area arrives in the traditional dominant key (F major). In contrast to the previous sonatas, here the development section elaborates on several different themes from the exposition. It reaches a dramatic climax in D minor, in which the first theme is presented, fluctuating between D minor and the home key, in a manner similar to the parallel passage from the previous sonata (see above). In the recapitulation, the bass line in the first theme rises to B-flat instead of descending to F (as in the exposition), and the second theme enters in B minor, instead of F-sharp minor. The rest of the exposition is repeated without alterations, transposed a fourth up, meaning that it returns to the home key, B-flat, for the third tonal area. The coda once again recalls the first theme, although only fragmentarily.

II. Andante sostenuto. This movement is written in ternary form, and is in the key of C-sharp minor – "the most tonally remote inner movement in Schubert's mature instrumental works in sonata form". In the main section, a somber melody is presented over a relentless rocking rhythm in a texture swimming in pedal. The central section is written in A major, and presents a choral melody over an animated accompaniment; it later touches upon B-flat major, the sonata's home key. The main section returns with a variant of the original accompanying rhythm. This time, the tonal scheme is more unusual: after a half cadence on the dominant, a sudden, mysterious harmonic shift introduces the remote key of C major. This eventually turns into E major, and proceeds as before. The coda shifts to the tonic major, but is still haunted by glimpses of the minor mode.

III. Scherzo: Allegro vivace con delicatezza – Trio. The first part of the scherzo proper cadences not in the tonic or dominant, but in the subdominant. The second, B part, continues to modulate by ascending fourths, until it reaches the key of D-flat major. In this key, a new theme is presented, emphasizing the local subdominant (G-flat major, a further fourth upward) – first in the major mode, then in the minor, with an enharmonic shift to F-sharp minor. This harmonic excursion eventually leads, through A major and a B diminished triad, back to the tonic and the opening section. The trio is in binary form and in B-flat minor, the first presentation of the tonic minor in the sonata.

IV. Allegro ma non troppo – Presto. The finale has the same structure as that of the previous sonata. Many elements of this movement imply large-scale resolution of harmonic and thematic conflicts established earlier in this and even the two previous sonatas. The main rondo theme opens with an 'empty' octave on G, which resolves to C minor, subsequently interpreted as ii of V in B-flat major. Brendel asserts that this theme, beginning in the ambiguous G/Cm, functions as a resolution of the troubling G♭ trill presented in the very beginning of the sonata, using G♭ to resolve to F major as V of B-flat. The second theme, in ternary form, is written in the traditional key of the dominant, with a central section in D major; it consists of an extended, characteristically Schubertian stepwise melody played over an uninterrupted flow of semiquavers. This second theme uses the same melodic contour (5-8-7-6-6-5-(5-4-4-3)) of the remarkable C major modulation in the final A section of the second movement, implying further connotations of conflict resolution. After an abrupt end to the second theme and a pregnant pause, a minor dotted-rhythm chordal theme in F-minor suddenly enters fortissimo, elaborating and modulating before sublimating into a pianissimo version of itself in the parallel major. This third theme is highly similar in rhythm and melodic contour as well as left hand pattern to the tarantella of the C minor sonata, which may not be a coincidence when considering the overall high level of cyclic connection between the sonatas. This theme evolves into a rhythmic segue that leads seamlessly back to the main theme of the rondo. The development section, based entirely on the rhythmic pattern of the main rondo theme, is characterised by juxtaposed eighth notes and triplets, reaching a climax on C-flat major, from which the bass descends in chromatic modulation eventually to G in an extended diminuendo to return to the main theme. In the coda, the main theme is fragmented in a manner also similar to the finale of the previous sonata; in a highly chromatic and unstable progression, the octave on G here descends through G-flat to F, in an extension of the G-G♭-F resolution of the theme. After finally reaching this dominant preparation for the final time, the movement closes with an exceedingly triumphant and affirming presto section that totally resolves all dramatic conflicts in the sonata and the series.