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 comprise one of the most important collections of works in the history of music.Hans von Bülow called them "The New Testament" of music (Johann Sebastian Bach's The Well-Tempered Clavier being "The Old Testament").
Beethoven's piano sonatas came to be seen as the first cycle of major piano pieces suited to concert hall performance. Being suitable for both private and public performance, Beethoven's sonatas form "a bridge between the worlds of the salon and the concert hall".
Beethoven's early sonatas were highly influenced by those of Haydn and Mozart. Even so, he began to find new ways of composing his sonatas. His Piano Sonatas No. 1, 2, 3, 4, 7, and 11 were four movements long, which was very uncommon in his time.
Opus 2: Three Piano Sonatas (1795)
Opus 7: Piano Sonata No. 4 in E-flat major ("Grand Sonata") (1797)
Opus 10: Three Piano Sonatas (1798)
Opus 13: Piano Sonata No. 8 in C minor ("Pathétique") (1798)
Opus 14: Two Piano Sonatas (1799)
Opus 22: Piano Sonata No. 11 in B-flat major (1800)
After he wrote his first 13 sonatas (up to Op. 28), he wrote to Wenzel Krumpholz, "From now on, I'm going to take a new path." Beethoven's sonatas from this period are very different from his earlier ones. His experimentation in modifications to the common sonata form of Haydn and Mozart became more daring, as did the depth of expression. Most Romantic period sonatas were highly influenced by those of Beethoven. After 1804, Beethoven ceased publishing sonatas in sets and only composed them as a single opus. It is unclear why he did so.
Opus 26: Piano Sonata No. 12 in A-flat major ("Funeral March") (1801)