Polyphony

Polyphony, music consisting of two or more simultaneously sounding parts (in contrast to monophony, or music consisting solely of a single melodic line). Ethnomusicologists use the term polyphony to mean all instances of simultaneous parts (such as a drone and melody; or Western homophony; or African choral music), the one exception being simultaneous variations of a single melody (called heterophony).

In Western music history, polyphony is often given a narrower meaning: The simultaneous parts must be rhythmically distinct from one another. Polyphony in this sense overlaps somewhat with counterpoint (the technique of combining simultaneous parts or melodies), and the word polyphony often refers to the contrapuntal vocal music of the Middle Ages and the Renaissance. In this narrower, contrapuntal sense, polyphony is also contrasted with another musical texture—homophony, in which the simultaneous parts all have the same rhythm and create successions of chords, each chord being heard as a unit (as in typical four-part hymns).