polyphony

n. [ Gr. &unr_;. ] 1. Multiplicity of sounds, as in the reverberations of an echo. [ 1913 Webster ]

2. Plurality of sounds and articulations expressed by the same vocal sign. [ 1913 Webster ]

3. (Mus.) Composition in mutually related, equally important parts which share the melody among them; contrapuntal composition; -- opposed to homophony, in which the melody is given to one part only, the others filling out the harmony. See Counterpoint. [ 1913 Webster ]