The Piano Sonata No. 24 in F♯ major, Op. 78, nicknamed "à Thérèse" (because it was written for Countess Thérèse von Brunswick) was written by
Ludwig van Beethoven in 1809. It consists of two movements:
A typical performance takes about 8-9 minutes. The common practice of leaving out long repeated sections, such as the development and recapitulation in the first movement, would make two or three minutes' difference to the total duration.
According to
Carl Czerny, Beethoven himself singled out this sonata and the "
Appassionata" Sonata as favourites (once written, the "
Hammerklavier" Sonata" would also become one of Beethoven's favourites).