Changing Expectations: Schubert’s Piano Trio in E-flat

The romantic era was a fertile period in the history of musical experimentation, and traditional musical forms such as the sonata, were undergoing interesting and unexpected transformations. The works of Haydn and Mozart laid the foundation for this development, but by the nineteenth century audiences knew what to expect so that composers were hard pressed to push the boundaries. One particular innovative example is the first movement of the Trio for Piano and Strings No 2 in E-flat Major, D 929 / Op. 100, by Austrian composer Franz Schubert, completed just one year before his death. The work deviates from the norm taking the listener on a true musical adventure.

The sonata form traditionally presents two contrasting musical ideas, develops these ideas, and concludes by returning to them; in musical terms, the three parts are exposition, development and recapitulation. Even jazz follows fundamentally similar principles by stating the head, improvising on it, and then restating it.

exposition

Schubert’s Allegro first movement opens with a unison melody played by the violin, cello, and piano (see Example 1). The opening high note falls by leaps as the notes get faster. The melody climbs almost halfway and then falls in three even faster notes. This introduction returns intact much later to signify our journey’s end.

Several bars later, as the volume drops, the cello sings what should be the first theme (see Example 2). The violin plays a quiet harmony and the piano is silent except for punctuation. This theme is characterized in its first measure by the neighbouring tone, a semi-tone below, which is the main feature in this entire movement.

The second theme traditionally provides contrast to the first, while still remaining within a closely related key, usually with six out of seven pitches in common with the opening key. Instead, Schubert disorients the listener with rapid chromatic piano runs then lands in the drastically remote key of B minor. Instead of having six notes in common with the opening key, he has only two – a more extreme change would be difficult to imagine. As if that were not enough, Schubert also switches from a major to a minor key, as demonstrated by the short, repeated chords – an effect similar to switching from sunlight to candlelight (Example 3). It is a pretty tune and Schubert develops it immediately, rather than waiting until the expected development section. The theme is repeated, moving through unexpected keys suggesting that we may already be into the development part, but that is not the case.

A brief allusion to the earlier neighbouring-tone motif brings us to yet another melody, a contrapuntal one in the strings, accompanied by a rippling stream of descending triplets in the piano. It is odd to have so many distinct themes in one piece. Schubert is not only pushing the boundaries of the traditional conception of a sonata, he is also pushing his audience's ability to follow and retain all of this thematic information.

The neighbouring-note motif returns here. This is actually the theme that will be developed during most of the next section and it is closely related to the earlier example, but has grow (Example 4). The theme begins with the same notes, an octave higher, and with the violin instead of the cello, which is instantly recognizable to the ear even though the rhythm has changed. Notes are now longer, but otherwise the first half of the theme is changed only by falling immediately to the C, rather than dropping through a B-flat arpeggio to the lower C. It is the second half of the theme that has evolved the most. In the earlier statement it was similar in rhythm and contour to the first phrase, but in this statement it is quite different. Although the many distinct themes make this a difficult piece to follow upon first listening to it, it becomes more fascinating during subsequent hearings. At the end of the exposition, there is a complete repetition of everything that has been heard so far, as if to ensure that nothing has been missed.

Development

The development section is similar in many ways to jazz improvisations. The themes for the piece are played with, expanded upon, passed through different keys and between the various instruments. The main theme for the development is the neighbouring-tone theme, as it appears in Example 4, though not in its initial statement. Schubert works this theme through radical key changes before eventually bringing it home. The first key change is to B minor, the key that figured as prominently as other themes from the exposition. From there the music jumps a tri-tone to F - remember that a tri-tone is the most dissonant relationship possible in music. Next, the theme shifts up a semi-tone to F sharp. Schubert turns a completely unexpected shift into a completely normal one. The combination of the tri-tone and semi-tone gives us a perfect fifth, one of the most consonant relationships in music and a common key change in the development of a piece. He repeats this process again by modulating to C, the tri-tone of F-sharp, then modulating to D-flat, the enharmonic equivalent of the fifth of F-sharp. The D-flat then changes to C-sharp minor. This is wonderful to hear - D-flat and C-sharp are the same note on a piano and virtually the same on the violin and cello, but this change shows the importance of the contrast of major to minor to this piece. Then, the theme moves into E minor, and shifts up a semi-tone to return smoothly to E-flat, the original key of the piece. Even knowing the path that the development takes, it is a captivating listen as Schubert leads the audience down this complicated path with its sudden twists and turns. Then, just when it seems that we are completely lost he turns a corner and brings us back home.

Recapitulation

The return of the introduction signals the end of the development section and the start of the recapitulation. Schubert actually stays quite close to what is expected here and repeats the exposition entirely in E-flat as a normal sonata ought to do. This is not yet the end of the movement, though. The neighbouring-semi-tone motif reappears, followed by the minor theme, and finally the introductory theme returns one last time to round out the movement. Overall this Allegro movement is an excellent example of how the concept of sonata form, and indeed all of the traditional forms, grew throughout the romantic era. Schubert challenged expectations by seeming to present more thematic material than one would normally expect, then evolving the first theme into the main theme. He made drastic modulations then shifted subtly to arrive at a not-so-far-away key. Finally, he unexpectedly developed the minor theme within the exposition itself before focusing on the main one in the development section. These challenges to the audience’s expectations keep the piece exciting to listen to, even now, almost 200 years after its premiere! n