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
Double harmonic scale harmonic minor scales respectively, each of which, unlike the double harmonic minor scale, has a full diminished chord backbone. This scale (and its modes like the Hungarian minor scale) is the only seven-note scale (in 12-tone equal temperament) that is "perfectly balanced"; this means that when its pitches are represented as points on a circle (whose full circumference represents an octave), their average position (or "centre of mass") is the centre of the circle. Like most heptatonic (seven-pitch) scales, the double harmonic scale has a mode for each of its individual scale degrees. The most commonly known of these modes