The aria da capo is a formal song structure developed in Italian opera in the late 17th century. It uses a three-part structure, in which the beginning section is repeated after a contrasting middle section. Though this formal scheme was first used by Monteverdi, he did not designate it aria da capo. This type of aria achieved artistic perfection in the operatic works of Alessandro Scarlatti, and in the great choral works of Bach and Handel. The aria da capo declined in the 18th century as composers (and their virtuoso singers) began to further subdivide and rearrange the three main sections.