A concerto is a classical music composition that highlights a solo instrument against the background of a full orchestra. Bach is one composer known for writing concertos.
In a concerto, a piano, violin, flute, or other instrument plays solo parts that are backed up or highlighted by an orchestra. Most concertos have three sections or movements, and in the 19th century they were especially popular as a way to showcase virtuoso playing by the soloist. In Italian, concerto means "concert or harmony," from concertare, "to bring into agreement."