Horwell comma
Interval information |
reduced harmonic
(Shannon, [math]\sqrt{nd}[/math])
The horwell comma (monzo: [-16 1 5 1⟩, ratio: 65625/65536) is an unnoticeable 7-limit comma measuring about 2.35 cents. It is the difference between 32/21, the septimal superfifth, and a stack of five 5/4's octave reduced.
Temperaments
Tempering out this comma leads to the horwell temperament, where 32/21 can be found through a stack of five 5/4's and octave reduction. See Horwell family for the rank-3 family where it is tempered out. See Horwell temperaments for a collection of rank-2 temperaments where it is tempered out.
Etymology
This comma was first named as tertiapont by Gene Ward Smith in 2005 as a contraction of tertiaseptal and pontiac[1]. It is not clear how it later became horwell, but the root of horwell is obvious, being a contraction of hemithirds and orwell.