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 Concerto No. 1 (Beethoven)
Although this was Beethoven's first piano concerto to be published, it was actually his third attempt at the genre, following an unpublished piano concerto in E-flat major of 1784 (not to be confused with Beethoven's more famous "Emperor" concerto, also in E-flat) and the Piano Concerto No. 2. The latter was published in 1801 in Leipzig after the Piano Concerto No. 1, but was composed over a period of years, perhaps beginning ca. 1788. Its first performance took place on 29 March 1795, several months before the concerto now referred to customarily as "No. 1".