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
Tonic sol-fa latter more directly represents the intervals between pitches in any given key signature. In Curwen's system, the notes of the major scale (of any key) are notated with the single letters d, r, m, f, s, l, and t. For notes above the principal octave, an apostrophe follows the letter; notes below the principal octave have a subscript mark. Chromatic alterations are marked by the following vowel, "e" for sharp (pronounced "ee") and "a" for flat (pronounced "aw"). Thus, the ascending and descending chromatic scale is notated: Such chromatic notes appear only as ornaments or as preparation for a modulation;