Ludwig van Beethoven wrote 32 mature piano sonatas between 1795 and 1822. (He also wrote 3 juvenile sonatas at the age of 13 and one unfinished sonata, WoO. 51.)Although originally not intended to be a meaningful whole, as a set they comprise one of the most important collections of works in the history of music. Hans von Bülow called them "The New Testament" of piano …