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:
Blues scale Blues scale The term blues scale refers to several different scales with differing numbers of pitches and related characteristics. The hexatonic, or six-note, blues scale consists of the minor pentatonic scale plus the 5th degree of the original heptatonic scale. This added note can be spelled as either a 5 or a 4. \override Score.TimeSignature #'stencil = ##f \relative c' { </score> A major feature of the blues scale is the use of blue notes; however, since blue notes are considered alternative inflections, a blues scale may be considered to not fit the traditional definition of a scale. At its