chamber music, ensemble music for small groups of instruments, with only one player to each part. Its essence is individual treatment of parts and the exclusion of virtuosic elements. Originally played by amateurs in courts and aristocratic circles, it began to be performed by professionals only in the 19th cent. with the rise of the concert hall. In the broadest sense it existed as early as the Middle Ages. The ricercare and the concerted canzone of the 16th cent. are properly chamber music, although unlike later forms they were not for specific instruments but were usually performed by voices and whatever instruments were at hand. During the baroque period the chief type was the trio sonata. About 1750 the string quartet with its related types—trio, quintet, sextet, septet, and octet—arose. As developed by Haydn and Mozart the quartet became the principal chamber-music form. It was used by Beethoven and Schubert, whose quartets are the last of the classical period, and by the chief composers of the romantic period—Mendelssohn, Schumann, Brahms, Dvořák, Franck, d'Indy, and Reger. In the early 20th cent. the coloristic possibilities of the quartet were exploited by Debussy and Ravel. More recently the different forms of chamber music have been used extensively for experiments in atonality, percussive rhythms, and serial techniques by such composers as Schoenberg, Bartók, Webern, Berg, Stravinsky, Sessions, and Piston.
See D. F. Tovey, Essays in Musical Analysis: Chamber Music (1944, repr. 1989); W. W. Cobbett, ed., Cyclopedic Survey of Chamber Music (3 vol., 2d ed. 1963, repr. 1987); H. E. Ulrich, Chamber Music (2d ed. 1966); M. Berger, Guide to Chamber Music (1985); J. M. Keller, Chamber Music: A Listener's Guide (2010).