The minor scales · Music theory
Natural, harmonic and melodic, the leading tone and the key signatures of minor keys.
The natural minor scale
The natural minor scale (or Aeolian) is whole, half, whole, whole, half, whole, whole: the half steps fall between II and III and between V and VI. Its 3rd above the tonic is minor, and that gives it the character of the minor mode.
Each minor scale shares its notes with a major one, its relative: A minor has the same notes as C major, starting on A. The relative minor lies a minor 3rd below the major, on its degree VI.
Major and minor, face to face
Compared with its parallel major, the natural minor has three degrees one accidental lower: III, VI and VII. C major has E, A and B; C natural minor, E♭, A♭ and B♭. What defines the mode is above all III: the 3rd above the tonic is the first thing the ear notices.
Historically, this scale coincides with the Aeolian mode, which Heinrich Glarean added in 1547 to the eight church modes. The harmonic and melodic forms are later adaptations, so that the minor mode would have the same cadential strength as the major.