Diaschismic–gothmic equivalence continuum

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The diaschismic-gothic equivalence continuum, also referrable as the diaschismic-würschmidt equivalence continuum, diaschismic-kleismic equivalence continuum, or kleismic-würschmidt equivalence continuum, is a continuum of 5-limit temperaments that describes the set of all 5-limit temperaments supported by 34edo.

All temperaments in the continuum satisfy (2048/2025)n ~ [27 -17, equating a number of diaschismas (2048/2025) with the gothic comma. Varying n results in different temperaments listed in the table below. It converges to diaschismic as n approaches infinity. If we allow non-integer and infinite n, the continuum describes the set of all 5-limit temperaments supported by 34edo due to it being the unique equal temperament that tempers out both commas and thus tempers out all combinations of them. The just value of n is approximately 3.41464…, and temperaments having n near this value tend to be the most accurate ones.

The gothic comma is the characteristic 3-limit comma tempered out in 34edo. Describing the continuum this way has notable advantages – in particular, due to being determined in terms of the 3-limit comma and the comma with the next lowest power of 5, twice the numerator of the value of n represents the number of generator steps required to reach the interval class of 3.

Another reasonable way of defining this continuum equates a number of diaschismas with the würschmidt comma (393216/390625), so that (2048/2025)k ~ 393216/390625. As a result, k = 4 - n, and this labeling may also be called the diaschismic-würschmidt equivalence continuum. The just value of k is 0.5853…, and temperaments near this tend to be the most accurate.

Temperaments with integer n and k
k n Temperament Comma
Ratio Monzo
4 0 Gothic 134217728/129140163 [27 -17
3 1 Immunity 1638400/1594323 [16 -13 2
2 2 Tetracot 20000/19683 [5 -9 4
1 3 Hanson 15625/15552 [-6 -5 6
0 4 Würschmidt 393216/390625 [17 1 -8
-1 5 Mabila 268435456/263671875 [28 -3 -10
-2 6 Goldis 549755813888/533935546875 [39 -7 -12
∞* Srutal 2048/2025 [11 -4 -2
* in projective tuning space, ∞ = -∞.

All temperaments in the continuum also satisfy (15625/15552)s ~ 393216/390625, for a value of s defined such that 1/k - 1/s = 1; equivalently, we can offset s by 1, and equate a number of kleismas (15625/15552) with the diaschisma, giving rise to the name diaschismic-kleismic equivalence continuum. Varying s results in different temperaments listed in the table below. It converges to hanson as s approaches infinity, and is motivated by the fact that many important temperaments of 34edo follow a chain of commas connected by kleismas.

Temperaments with integer s in the kleismic-würschmidt continuum
s Temperament Comma
Ratio Monzo
-4 34 & 113 152587890625/148769467776 [-7 -19 16
-3 Fifive 9765625/9565938 [-1 -14 10
-2 Tetracot 20000/19683 [5 -9 4
-1 Srutal 2048/2025 [11 -4 -2
0 Würschmidt 393216/390625 [17 1 -8
1 Vishnu 6115295232/6103515625 [23 6 -14
2 Gammic (28 digits) [-29 -11 20
3 Quatracot (38 digits) [-35 -16 26
Hanson 15625/15552 [-6 -5 6
Temperaments with fractional k and s
s k n Temperament Comma
1/2 = 0.5 1/3 = 0.3 11/3 = 3.6 Majvam [40 7 -22
3/2 = 1.5 3/5 = 0.6 17/5 = 3.4 Chlorine [-52 -17 34
-1/3 = -0.3 -1/2 = -0.5 9/2 = 4.5 34 & 142 [45 -2 -18