Homophony is a musical texture consisting of several simultaneous parts, the highest of which usually predominates, with the others functioning to form chords for that melody. These secondary parts also sometimes provide a rhythmic contrast to that of the primary melody. Homophony differs from polyphony, which has relatively more independent parts, with their independence tending to be reinforced by their distinctive rhythms, and from monophony, in which all parts move in unison or in octaves.