Harmonic scale It was invented by Wendy Carlos and used on three pieces on her album "Beauty in the Beast" (1986): "Just Imaginings", "That's Just It", and "Yusae-Aisae". Versions of the scale have also been used by Ezra Sims and Frans Richter Herf. Though described by Carlos as containing "144 [= 12] distinct pitches to the octave", the twelve scales include 78 (= ) notes per octave. Technically there should then be duplicates and thus 57 (= 78 − 21) pitches (21 = ). For example, a perfect fifth above G (D) is the major tone above C. Harmonic scale The Harmonic
Hexatonic scale Others have referred to it as the "Promethean chord". Since blue notes are alternate inflections, strictly speaking there can be no one blues scale, but the scale most commonly called "the blues scale" comprises a flatted seventh blue note, a flatted third blue note, and a flatted fifth blue note along with other pitches derived from the minor pentatonic scale: C E F G G B C. The tritone scale, C D E G G() B, is enharmonically equivalent to the Petrushka chord, C C E F G A. The "two-semitone tritone scale", C D D F G A, is