Polyphony
From BiblePortal Wikipedia
Polyphony [1]
(1): ( n.) 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.
(2): ( n.) Plurality of sounds and articulations expressed by the same vocal sign.
(3): ( n.) Multiplicity of sounds, as in the reverberations of an echo.