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:
Bebop scale as the bebop minor scale) is derived from the Dorian mode and has a chromatic passing tone between the minor 3rd and the perfect 4th. \override Score.TimeSignature #'stencil = ##f \relative c' { </score> It has all the notes in both the Dorian scale and the Mixolydian scale of the same root. It is the 5th mode of the bebop dominant scale. A second form of the bebop Dorian scale features a major seventh bebop note between the dominant seventh and the tonic. \override Score.TimeSignature #'stencil = ##f \relative c' { </score> The second style, featuring the major seventh, is