18th-Century Polyphonic Instrumental Music

Contrapuntal forms of the Baroque were not completely discarded during the Classic period. They were, however, most often used as musical devices rather than complete forms. For example, the first theme in sonata form was sometimes cast as a "fugato" (fugal passage). Fugal passages were also often used in the development sections of sonatas. Both Haydn and Mozart made extensive use of fugue in this manner and used polyphonic principles of construction in independent works as well as throughout complete movements in some of their multi-movement works. In contrast to the Baroque fugue, however, their subjects were usually longer and more lyrical.