Piano sonatas (Beethoven)
Ludwig van Beethoven wrote his 32 piano sonatas between 1795 and 1822. Although originally not intended to be a meaningful whole, as a set they compose one of the most important collections of works in the history of music. Hans von Bülow called them "The New Testament" of the piano literature (Johann Sebastian Bach's "The Well-Tempered Clavier" being "The Old Testament").
Piano Sonata No. 9 (Beethoven)
The Piano Sonata No. 9 in E major, Op. 14, No. 1, is an early-period work by Ludwig van Beethoven, dedicated to Baroness Josefa von Braun, one of his patrons at that time. It was composed in 1798 and arranged for string quartet by the composer in 1801 (Hess 34), the result containing more quartet-like passagework and in the more comfortable key of F major.