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").
Sonatas for viola da gamba and harpsichord (Bach)
Although the dating of Bach's three sonatas for viola da gamba and cembalo has presented problems for musicologists, because only an autograph score of the first sonata BWV 1027 survives, there is now general consensus that the works were written in Leipzig at some time in the late 1730s and early 1740s. Prior to that commentators had suggested that they dated from an earlier period when Bach was in Cöthen or even beforehand: the viola da gamba player Christian Ferdinand Abel was one of the court musicians of Prince Leopold at Cöthen. Bach moved to Leipzig as Thomaskantor in 1723 and in 1729 was appointed director of the Collegium Musicum, a chamber music society that put on weekly concerts at the Café Zimmermann.