Franz Schubert composed his Fantasy (German: Fantasie; French: Fantaisie) in C major for violin and piano, Op. posth. 159, D 934, in December 1827. It was the last of his compositions for violin and piano, and was premiered in January 1828 by the violinist
Josef Slavik and the pianist
Carl Maria von Bocklet at the Landhaussaal in Vienna.
The difficult work was "calculated to display Slavík's virtuoso [violin] technique" and is demanding for both instruments. According to pianist Nikolai Lugansky, the Fantasy "is the most difficult music ever written for the piano", and "more difficult than all of
Rachmaninov’s [piano] concertos put together".
The second movement, Andantino, is a reworking of Schubert's earlier song "Sei mir gegrüßt" (D 741, 1821-22), formatted as a theme and variations.