Some composers of modern avant-garde music have embraced the use of microtonal scales, dividing an octave into 19, 31, 43 and other numbers of pitches, rather than the more common 12. The intervals between pitches can be equal, creating an equal temperament, or unequal, such as in just intonation. Microtones include quarter tones[?] and twelfth tones[?] (octave divided into 24 and 72 equal parts).
Pioneers of modern Western microtonal music include: