POLYPHONY (from Gk. roNvOcovia, polypho nic, variety of sounds. from roMq5umos, polypho nos, baying many sounds, from roXtis, po/gS, much. many + Ocov-if', ph/Tim', sound, voice). In musical composition, the combination in har monious progressions of two or more' parts, each of which has an independent melody of its OWn. Polyphony is opposed to homophony (OX.). which consists of a principal part with a leading idea and accessory parts furnishing the harmony. The construction of polyphonic phrases is called. counterpoint (q.v.). Aliont the ninth century we find the beginnings of modern polyphony in oryanum q.v. or diaph (my. which was the pro gression of parts in parallel fifths or fourths. In these first attempts at polyphony there are many dissonances which seem to us intolerable: hut in the course of time eonpose•s learned the secret of obviating the harsh effects by using the intervals in proper succession. and the next
step was the combining of two voices into a real harmonic structure. Instead of the melody being only in one voice, ns in the following example from Guido d'Arczzo (q.v.), NN bile the second voice intoned an urpn-point iq.v. 1, we have a distinct melody in each voice. as in the following example from the fourteenth century : When polyphony still further developed and three and four voices were employed, the additional voices were also given separate melodies as far as possible. Still polyphony as we now under stand it had not really begun, for, though the voices were combined in all harmonic whole. they did not all assist in the development of a single idea. Composition had musical hut not structural unity. With the rise of the great Flemish School (see Nusic, SCHOOLS