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:
Scale (music) pitches. A common scale in Eastern music is the pentatonic scale, which consists of five notes that span an octave. Some scales span part of an octave; Several such short scales are typically combined to form a scale spanning a full octave or more, and usually called with a third name of its own. The Middle Eastern music has around a dozen such basic short scales that are combined to form hundreds of full-octave spanning scales. Among these middle eastern scales Hejaz scale has one scale step spanning 14 intervals (of the middle eastern type found 53 in an octave)