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
Pentatonic scale Pentatonic scale A pentatonic scale is a musical scale with five notes per octave, in contrast to the more familiar heptatonic scale that has seven notes per octave (such as the major scale and minor scale). Pentatonic scales were developed independently by many ancient civilizations—an indication that pentatonic scales are based upon a naturally occurring phenomenon. They are still used all over the world, for example (just to name a few) Chinese music and US country music and blues. There are two types of pentatonic scales: those with semitones (hemitonic) and those without (anhemitonic). Pentatonic scales occur in the following