4th-octave temperaments

Revision as of 12:48, 2 July 2026 by FloraC (talk | contribs) (- duplicate data)

4edo is much less used as a scale, rather as a chord. In many diatonic-based interval region schemes, one step of 4edo is known as a minor third, and the stacking of them is the diminished seventh chord.

Usage of the 6/5 minor third as one step of 4edo by tempering out 648/625, and therefore using 4edo as a diminished seventh chord produced by stacking three minor thirds is one of the features of standard Western music theory, and is supported by 12edo. See Diminished family for a collection of such temperaments.

19/16, the 19th harmonic octave-reduced, is much closer to quarter-octave than 6/5, and while it is not a microtemperament, a lot of equal divisions support it.

An interval closer to 1\4 is 25/21, with the associated comma being the dimcomp comma. See Dimcomp family for a collection of rank-3 temperaments tempering it out.

There are nonetheless other less common temperaments which divide the octave in four.

Temperaments discussed elsewhere are:

ViewTalkEditFractional-octave temperaments 
1st • 2nd • 3rd • 4th-octave • 5th • 6th • 7th • 8th • 9th →