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").
Violin Sonata No. 1 (Beethoven)
Ludwig van Beethoven's Violin Sonata No. 1 in D major is a violin sonata from his Op. 12 set, along with his Violin Sonata No. 2 and Violin Sonata No. 3. It was written in 1798 and dedicated to Antonio Salieri. Being an early work written around the period when Beethoven studied with Haydn, the sonata is for the most part written in a classical style much like that of Mozart or Haydn.