Sergei Prokofiev's Piano Sonata no. 5 in C major, Op. 38 (1923) and Op. 135 (revised 1952-53) is a sonata for solo piano. Prokofiev composed the sonata in Ettal, by the Bavarian Alps, and dedicated it to Pierre Souvtchinski, a musicologist and friend. Even though the revised version of the sonata has a new opus number, if one compares the two versions closely, there are few radical differences between the two, with most of the changes occurring in the last movement. This sonata was the only piano piece of this genre to be composed during his life outside of Russia.