Aeolian

What it means

The Aeolian mode is the scale that runs on the natural notes from A to A. It is identical to the natural minor: its semitone steps lie between the second and third and between the fifth and sixth degrees. The seventh degree lies a whole tone below the final, so there is no leading tone.

The spellings "Aeolian" and "Æolian" are equivalent and denote the same mode; the older ligature form makes the Greek origin of the name more visible.

Musical use

In the original ordering of the church modes the Aeolian did not appear; it was admitted to the system only in the sixteenth century, together with the Ionian, long after practice had in fact been following them. From these two, minor and major developed in the seventeenth century as the dominant tonal genders.

The difference from later minor lies above all in the leading tone. Major-minor tonality raises the seventh degree to obtain a cadential pull — from which the harmonic and melodic forms of the minor scale arise. The Aeolian mode keeps the low seventh degree and therefore sounds less goal-directed, softer, more archaic. It is precisely this sound that is sought in folk music, folk revival and popular music, where minor without a leading tone is widespread.

Aeolian is to be distinguished from Dorian, which differs only in the sixth degree — this lies a semitone higher there and gives the mode its floating character.

As an independent mode, Aeolian was first described in 1547 by Heinrich Glarean in his Dodecachordon, which expanded the received eight church modes to twelve. Later major-minor tonality adopted the Aeolian mode as the basic form of minor, but altered it in the cadence through the leading tone. In rock and pop music, in folk and in film music, the Aeolian form with its minor seventh remains widespread, for instance in chord progressions that do without a dominant carrying a major third.

Performance practice

In a minor piece, first check whether the seventh degree is raised: if the leading tone is missing, do not phrase toward a cadence that is not there. Sing the scale and attend to the two semitone points. And resist the habit of unconsciously raising the seventh degree as you play.