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. 0 (Beethoven)
Beethoven most likely composed this concerto in 1784, when he was still in Bonn. During this time period, Mozart had not yet composed his Symphonies No, 39, 40, or 41. Beethoven went to Vienna in 1792 at the age of 21.