Aeolian mode

The Aeolian mode is a musical mode or, in modern usage, a diatonic scale also called the natural minor scale. On the piano, using only the white keys, it is the scale that starts with A and continues to the next A only striking white keys.

Its ascending interval form consists of a key note, whole step, half step, whole step, whole step, half step, whole step, whole step. That means that, in A aeolian (or A minor), a scale would be played beginning in A, move up a whole step (two piano keys) to B, move up a half step (one piano key) to C, then up a whole step to D, a whole step to E, a half step to F, a whole step to G, and a final whole step to a high A.

History

The word Aeolian, like the names for the other ancient Greek tonoi and harmoniai, is an ethnic designation: in this case, for the inhabitants of Aeolis (Αἰολίς), a coastal district of Anatolia. In the music theory of ancient Greece, it was an alternative name (used by some later writers, such as Cleonides) for what Aristoxenus called the Low Lydian tonos (in the sense of a particular overall pitching of the musical system—not a scale), nine semitones higher than the lowest "position of the voice", which was called Hypodorian. In the mid-16th century, this name was given by Heinrich Glarean to his newly defined ninth mode, with the diatonic octave species of the natural notes extending one octave from A to A—corresponding to the modern natural minor scale. Up until this time, chant theory recognized eight musical modes: the relative natural scales in D, E, F and G, each with their authentic and plagal counterparts, and with the option of B♭ instead of B♮ in several modes.

In 1547, Heinrich Petri published Heinrich Glarean's Dodecachordon in Basel. His premise had as its central idea the existence of twelve diatonic modes rather than eight, including a separate pair of modes each on the finals A and C. Finals on these notes, as well as on B♮, had been recognized in chant theory at least since Hucbald in the early tenth century, but they were regarded as merely transpositions from the regular finals a fifth lower. In the eleventh century, Guido d'Arezzo, in chapter 8 of his Micrologus, designated these transposed finals A, B♮, and C as "affinals", and later still the term "confinal" was used in the same way.