Fantasie for Violin and Piano in C major, op. 159, D. 934

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".

A typical performance lasts around 25 minutes.