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:
Major scale semitone (i.e. whole, whole, half). The major scale is maximally even. \override Score.TimeSignature #'stencil = ##f \relative c' { </score> The scale degrees are: \override Score.TimeSignature #'stencil = ##f </score> The triads built on each scale degree follow a distinct pattern. The roman numeral analysis is shown in parentheses. If a piece of music (or part of a piece of music) is in a major key, then the notes "in" the corresponding major scale are considered "diatonic" notes, while the notes "outside" the major scale are considered "chromatic" notes. Moreover, the key signature of the piece of music (or section)