The term Concerto (from the concerto, plural concerti or the anglicised form concertos) usually refers to a three-part musical work in which one solo instrument is accompanied by an orchestra. The concerto, as understood in this modern way, arose in the Baroque period side by side with the concerto grosso, which contrasted a small group of instruments with the rest of the orchestra. While the concerto grosso is confined to the Baroque period, the solo concerto has continued as a vital musical force to this day.