Concerto

a multimovement composition (usually three movements) for solo instrument or instruments and orchestra

Appeared in the late Renaissance. The term is probably a derivative of the Latin word concertare=to contend; referring to competing or contrasted groups. Solo concerto was first introduced by Torelli, and further developed by Albinoni and Vivaldi. The Baroque solo concerto usually has outer movements written in ritornello form with a tonal plan close to that of da capo aria. As the only Baroque form survived into the Classical era, the concerto remained in three movements since its emergence.