Diatonic scale are major scales (those with a major third/triad: Ionian, Lydian, and Mixolydian), three are minor (those with a minor third/triad: Dorian, Phrygian, and Aeolian). To these may be added the seventh diatonic scale, with a diminished fifth above the reference note, the Locrian scale. These could be transposed not only to include one flat in the signature (as described by Glarean), but to all twelve notes of the chromatic scale, resulting in a total of eighty-four diatonic scales. The modern musical keyboard originated as a diatonic keyboard with only white keys. The black keys were progressively added for several purposes:
Chromatic circle major (Ionian mode), minor (Aeolian mode) and Mixolydian - include these pitches. Symmetric scales have simple representations in this scheme. More exotic scales - such as the pentatonic, blues and octatonic - can also be drawn and related to the common scales. A more complete list of musical scales and modes In previous sections we saw how various overlays (scale degrees, semi-tone numbering, notes) can be used to notate the circumference of the constellation. Various other overlays can be laid around the constellation. For example: Note that once a pitch constellation has been determined, any number of overlays (notes, solfège,