Cantonisma
The cantonisma is an unnoticeable comma of the 13-limit with a ratio of 10985/10976 and a value of approximately 1.42 cents. It forms the difference by which a stack of three 14/13's (trienthirds) falls short of 5/4 (classical major third). It factors into (1716/1715)⋅(4225/4224).
| Interval information |
Temperaments
Tempering out this comma in the 13-limit leads to the rank-5 cantonismic temperament, or in the 2.5.7.13 subgroup, the rank-3 cantonic temperament. It is tempered out in such notable edos as 10, 19, 27, 38, 46, 84, 103, 121, 130, 224, 270, 494 and 764, leading to a variety of temperaments in which three trienthirds make up a 5/4 major third.
Etymology
This comma was named by Margo Schulter in 2013 after Gene Ward Smith's Canton scale[1].