Superpyth–22 equivalence continuum

Revision as of 09:07, 23 July 2024 by FloraC (talk | contribs) (+commas for fractional-numbered temps)

The superpyth-22 equivalence continuum is a continuum of 5-limit temperaments which equate a number of superpyth commas, 20480/19683 = [12 -9 1, with the 22-comma, [35 -22. This continuum is theoretically interesting in that these are all 5-limit temperaments supported by 22edo.

All temperaments in the continuum satisfy (20480/19683)n ~ 250/243. Varying n results in different temperaments listed in the table below. It converges to 5-limit superpyth as n approaches infinity. If we allow non-integer and infinite n, the continuum describes the set of all 5-limit temperaments supported by 22edo due to it being the unique equal temperament that tempers both commas and thus tempers all combinations of them. The just value of n is approximately 2.284531…, and temperaments having n near this value tend to be the most accurate ones.

Temperaments in the continuum
n Temperament Comma
Ratio Monzo
0 22 & 22c (22 digits) [35 -22
1 Quasisuper 8388608/7971615 [23 -13 -1
2 Diaschismic 2048/2025 [11 -4 -2
3 Porcupine 250/243 [1 -5 3
4 Comic 5120000/4782969 [13 -14 4
5 22 & 3cc (23 digits) [25 -23 5
Superpyth 20480/19683 [12 -9 1

We may also invert the continuum by setting m such that 1/m + 1/n = 1. This may be called the quasisuper-22 equivalence continuum, which is essentially the same thing. The just value of m is 1.778495…

Temperaments in the continuum
m Temperament Comma
Ratio Monzo
0 22 & 22c (22 digits) [35 -22
1 Superpyth 20480/19683 [12 -9 1
2 Diaschismic 2048/2025 [11 -4 -2
3 22 & 29c (22 digits) [34 -17 -3
Quasisuper 8388608/7971615 [23 -13 -1
Temperaments with fractional n and m
n m Temperament Comma
11/5 = 2.2 11/6 = 1.83 Hendecatonic [43 -11 -11
9/4 = 2.25 9/5 = 1.8 Escapade [32 -7 -9
16/7 = 2.285714 16/9 = 1.8 Kwazy [-53 10 16
7/3 = 2.3 7/4 = 1.75 Orson [-21 3 7
5/2 = 2.5 5/3 = 1.6 Magic [-10 -1 5