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
Insen scale Insen scale Insen (or In Sen) is a tuning scale adapted from shamisen music by Yatsuhashi Kengyō for tuning of the koto. It only differs from the hirajoshi scale by one note. In D mode it consists of: D-E-G-A-C so it has the same notes as the Phrygian chord (7sus♭9). Other chords compatible with insen scale include M7♯11 when the scale is played half steps lower (for example B in sen scale for CM7♯11 chord) and Cm6 and Cm when the scale is played one full step above (for example D insen with Cm6 or Cm chord). Other scales related