The Piano Sonata no. 13 in A major D. 664, also catalogued as Op. posth. 120, is a sonata for solo piano composed by Franz Schubert in the summer of 1819. Well regarded among pianists, the "Little" A major sonata is so called to distinguish it from the hefty 1828 sonata in the same key. The manuscript was dedicated to Josephine von Koller of Steyr in Upper Austria, whom he considered to be "very pretty" and "a good pianist." The lyrical, buoyant, in spots typically poignant nature of this sonata fits the image of a young Schubert in love, living in a summery Austrian countryside, which he also considered to be "unimaginably lovely." The sonata is straightforward, with a dulcet melodic opening. The manuscript has been lost.