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
Hungarian minor scale indicates a half step, and + indicates an augmented second (the latter of which is enharmonically equivalent to a minor third but is notionally distinct). The scale contains two augmented seconds, one in each tetrachord. It also contains an augmented fourth (which is enharmonically identical to a tritone) between the first and fourth degree. Intriguingly, this scale (and its modes like the double harmonic scale) is the only seven-note subset of the equally tempered chromatic scale that is "perfectly balanced"; this means that when its pitches are represented as points in a circle (whose full circumference represents an octave), their