Chromatic scale Chromatic scale The chromatic scale is a musical scale with twelve pitches, each a semitone above or below its adjacent pitches. As a result, in 12-tone equal temperament (the most common temperament in Western music), the chromatic scale covers all 12 of the available pitches. Thus, there is only one chromatic scale. Moreover, in equal temperament, all the semitones have the same size (100 cents). As a result, the notes of an equal-tempered chromatic scale are equally-spaced. This makes the chromatic scale a nondiatonic scale with no tonic because of the symmetry of its equally-spaced notes. The ascending and descending
Bohlen–Pierce scale Bohlen–Pierce scale The Bohlen–Pierce scale (BP scale) is a musical tuning and scale, first described in the 1970s, that offers an alternative to the octave-repeating scales typical in Western and other musics, specifically the equal tempered diatonic scale. The interval 3:1 (often called by a new name, tritave) serves as the fundamental harmonic ratio, replacing the diatonic scale's 2:1 (the octave). For any pitch that is part of the BP scale, all pitches one or more tritaves higher or lower are part of the system as well, and are considered equivalent. The BP scale divides the tritave into 13 steps,