Franz Schubert composed his Sonata for piano, 4 hands, in B flat major, D. 617, in the summer of 1818, his first year of seasonal employment in Zseliz (situated in modern-day Slovakia). At the recommendation of a family friend in Vienna, the young musician had secured a favorable appointment there as a court musician to Count Johann Esterhazy and music tutor to the count's daughters. Originally the piano duo piece composed during this period bore the nickname "Grand Sonata," but was later published under the name "First Grand Sonata" in order to distinguish it from a subsequent four-hand piano sonata, the Sonata in C, D. 812. While the later duo sonata aspires to an almost symphonic scope, with its broad gestures and four-movement structure, the Sonata in B flat major is more evocative of a chamber-oriented posture. This owes to creative intent -- and perhaps the pleasant setting of the Esterhazy court -- rather than limitations of craft; after all, though Schubert was barely 21 at the time of the piece's composition, he had already proven himself prolific in virtually every instrumental genre. Though more modest in tone than its C major counterpart, the Sonata, D. 617, exhibits melodic invention as well as keen structural control and innovation. Both qualities are apparent in the first movement. In a characteristically unexpected deviation from the traditional sonata-form harmonic structure that the movement's classical contours would seem to suggest, Schubert moves from the B flat tonic of the opening theme to the highly irregular key of D flat major (rather than the expected dominant key of F). A structurally and affectively more expressive shift occurs in the Andante middle movement, which moves from D minor to D major in the outer sections of its ABA structure. In the third movement, Schubert really shows his precocious harmonic proclivities. The opening bars of this lively 6/8 movement pick up where the middle movement left off, in D major. With some clever chromatic slight of hand, however, Schubert reorients harmonic expectations by reinterpreting the tonal function of the middle movement's lingering D major, eventually settling into the B flat major key in which the whole work began, and in which the final movement ends. ~ Jeremy Grimshaw, All Music Guide
