- Harold S. Powers
The name assigned by Glarean in the Dodecachordon (1547) to the authentic mode on A, which uses the diatonic octave species a–a′, divided at e′ and composed of a first species of 5th (tone–tone–semitone–tone) plus a second species of 4th (semitone–tone–tone), thus a–b–c′–d′–e′ + e′–f′–g′–a′. With this octave species identical to that of the natural minor scale on A, the Aeolian mode, together with its plagal counterpart, the Hypoaeolian, closely resembles the descending melodic minor scale.
In the minor mode of tonal music (see Tonality) the dominant lies a 5th above the tonic, or principal scale degree, and the sixth degree is characteristically a semitone above the dominant; for this reason scholars in the last three centuries have tended to think of the minor mode of tonal music as a lineal descendant of Glarean's Aeolian scale. In fact the minor tonalities of tonal music are of heterogeneous origins. Even the key of A minor is indirectly but closely related historically to the old transposed modes 1 and 2 with finals on ...