concerto (kənchâr´tō), musical composition usually for an orchestra and a soloist or a group of soloists. In the 16th cent. concertare and concertato implied an ensemble, either vocal or instrumental. At the end of the century concerto referred to music in which two ensembles contested with each other. By 1750 it meant music contrasting a full ensemble with soloists in alternation. The form known as concerto grosso is characterized by a small group of solo players contrasted with the full orchestra. Giuseppe Torelli (1658–1709) and Vivaldi established the concerto grosso in three movements, while Corelli used four or more, alternating fast and slow movements. These three composers were active in the development of all forms of the concerto in the baroque period. J. S. Bach's six Brandenburg concertos and the concertos of Handel represent the fullest development of the baroque type. Toward the end of the 18th cent. the solo concerto displaced the concerto grosso. Mozart established the classical concerto in three movements, the first of which is a fusion of ritornello form with the newer sonata form, for solo instrument and orchestra. Beethoven expanded the dimensions of this form, giving greater importance to the orchestra. In the 19th cent. Liszt unified the concerto by using the same themes in all movements. He used the concerto form as a showcase for virtuoso display in the solo. The concerto repertory is strongest in works for piano and violin as the solo instrument. In the 20th cent. renewed interest in the concerto grosso has been manifested by such composers as Hindemith, Bartók, and Schnittke. Although previously reliant on the principle of tonality, the solo concert adapted to atonality and serial music, as in the concertos of Schoenberg and Berg.
See A. Veinus, The Concerto (rev. ed. 1964); D. F. Tovey, Essays in Musical Analysis: Concertos (1936, repr. 1972).