POLYRHYTHM: music with several independent rhythms at the same time
POLYTONALITY: music in several independent keys at the same time (or almost the same time)
POLYCHORD: a dissonant chord created by superimposing consonant chords
MODERNISM: the early-20th-century artistic movement which discarded traditional style in favor of radically new techniques
PRIMITIVISM: the adoption by elite art of the values or styles of primitive art