Concerto, musical composition in which unequal musical forces play in opposition to each other, usually 1 solo instrument against a large orchestra. The 3- movement orchestral form was elaborated by J.S. Bach out of the concerto da camera, a type of chamber music. George Friedrich Handel added the cadenza (improvised or written out musical interlude for the soloist) as a regular feature. Wolfgang Amadeus Mozart set the style for the modern concerto: The orchestra announces an opening subject with a tutti (a passage for full orchestra), then takes a subordinate position when the solo instrument enters, thus establishing the pattern of interchanges.