Octatonic scale scale" . The twelve tones of the chromatic scale are covered by three disjoint diminished seventh chords. The notes from two such seventh-chords combination form an octatonic collection. Because there are three ways to select two from three, there are three octatonic scales in the twelve-tone system. Each octatonic scale has exactly two modes: the first begins its ascent with a whole step, while the second begins its ascent with a half step (semitone). These modes are sometimes referred to as the "whole step/half-step diminished scale" and the "half-step/whole step diminished scale", respectively. Each of the three distinct scales can
Yo scale A - B. This is illustrated below. The Ryūkyū scale appears to be derived from the yo scale with pitches raised. More recent theory emphasizes that it is more useful in interpreting Japanese melody to view scales on the basis of "nuclear tones" located a fourth apart and containing notes between them, as in the "min'yō" scale used in folk music, and whose pitches are equivalent to the second mode of the "yo" scale: Yo scale The "yo" scale, which does not contain minor notes, according to a traditional theory is a pentatonic scale used in much Japanese music including