Würschmidt

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Würschmidt is a rank-2 temperament and parent of the würschmidt family, characterized by tempering out the würschmidt comma, 393216/390625. It can be treated as analogous to schismatic with the roles of the primes 3 and 5 reversed, since würschmidt is generated by a classical major third (5/4), very slightly sharpened so that eight of them make the sixth harmonic (6/1), giving 3/2 the same complexity 5/4 does in schismatic, but with comparable accuracy on the part of the generator. Four generators, therefore, reach the interval 625/512, which is equated to 768/625 and functions as a neutral third.

For technical data, see Würschmidt family #Würschmidt.

Extensions

Another useful interpretation of the würschmidt comma is that it makes the interval of 25/24 equal to two-thirds the size of 16/15. This can be exploited, as 16/15 factorizes into near-2:1 parts as (24/23)×(46/45), and therefore it is illogical not to set 25/24 equal to 24/23 (and 128/125 equal to 46/45) as well and set the remainder, 46/45, equal to a third of 16/15, by tempering S24 = 576/575 and S462 × S47 = 12167/12150 in the 2.3.5.23 subgroup. 14 generators turn out to stack to 23/1, and notably, 6/1 stacked 7 times and 23/1 stacked four times (at 56 generators) differ only by the 0.59-cent comma 279936/279841.

Strong extensions to the 7-limit include septimal würschmidt (tempering out 225/224, finding 7 at +18 generator steps), worschmidt (tempering out 126/125, finding 7 at -13 generator steps), and whirrschmidt (tempering out 4375/4374, finding 7 at +52 generator steps), but these are either considerably higher-damage or much higher-complexity than 5-limit würschmidt. In fact, the best septimal extension may be the weak extension hemiwürschmidt, which splits the ~5/4 generator into two ~28/25's by tempering out 3136/3125 alongside 6144/6125 (notably, in the 2.3.5.7.23 subgroup, this is the extension that tempers out the tiny comma S161 = 25921/25920).

Therefore, it may be advisable to consider würschmidt a no-sevens system, specifically in the 2.3.5.11 subgroup, where an extension that equates 128/125 with 45/44 and therefore 625/512 with 11/9 (by tempering out 243/242 and 5632/5625), finding the 11th harmonic at 20 generators up, is highly natural in addition to the aforementioned extension to prime 23.

Interval chain

In the below, octave-reduced harmonics 1–125 are indicated in bold. All intervals are in the 625-odd limit.

# Cents* Approximate ratios
2.3.5.23 subgroup Add-11 extension
0 0.00 1/1
1 387.78 5/4, 144/115 69/55
2 775.55 25/16, 36/23 69/44, 352/225
3 1163.33 45/23, 125/64, 736/375 88/45, 108/55
4 351.10 92/75, 225/184, 625/512 11/9, 27/22
5 738.88 23/15, 192/125 55/36, 135/88
6 1126.66 23/12, 48/25 44/23
7 314.43 6/5, 115/96 55/46
8 702.20 3/2 121/81
9 1089.98 15/8, 216/115 207/110, 253/135
10 277.76 27/23, 75/64 88/75, 207/176
11 665.54 184/125, 135/92, 375/256 22/15, 81/55
12 1053.31 46/25, 675/368 11/6, 81/44
13 241.09 23/20, 144/125 55/48, 132/115
14 628.86 23/16, 36/25 33/23
15 1016.64 9/5, 115/64 165/92, 242/135
16 204.42 9/8 121/108
17 592.19 45/32, 162/115 253/180
18 979.97 81/46, 225/128 44/25
19 167.74 138/125, 405/368 11/10, 243/220
20 555.52 69/50, 864/625 11/8, 243/176
21 555.52 69/40, 216/125 55/32
22 555.52 27/25, 69/64 99/92
23 555.52 27/20, 345/256
24 555.52 27/16 253/150
25 555.52 135/128, 243/230 132/125, 253/240
26 555.52 243/184, 828/625 33/25, 253/192
27 555.52 207/125 33/20
28 555.52 207/200, 648/625 33/32
29 555.52 162/125, 207/160 165/128
30 555.52 81/50, 207/128 121/75
31 555.52 81/80 121/120

* In 5-limit CWE tuning

Tunings

Optimized tunings

Constrained Prime-Optimized Tunings
Weight-skew\Order Euclidean
Tenney (2.3.5) CTE: ~5/4 = 387.734¢
Weil (2.3.5) CWE: ~5/4 = 387.776¢
Tenney (2.3.5.23) CTE: ~6/5 = 387.734¢
Weil (2.3.5.23) CWE: ~6/5 = 387.781¢
Destretched Prime-Optimized Tunings
Weight-skew\Order Euclidean
Tenney (2.3.5) POTE: ~5/4 = 387.7993¢
Tenney (2.3.5.23) POTE: ~6/5 = 387.8051¢
DR and equal-beating tunings
Optimized chord Generator value Polynomial Further notes
3:4:5 (+1 +1) ~5/4 = 387.4975 g8 + 8g - 16 = 0 1-3-5 equal-beating tuning, close to 3/29-comma
4:5:6 (+1 +1) ~5/4 = 388.1207 g8 - 8g + 8 = 0 1-3-5 equal-beating tuning, close to 3/19-comma
10:12:15 (+2 +3) ~5/4 = 388.2216 g8 - 2g7 + 4 = 0 Close to 1/6-comma
15:18:23 (+3 +5) ~5/4 = 387.9215 4g7 - 3g5 - 10 = 0

Tuning spectrum

The below assumes the 2.3.5.11.23 subgroup extension. Note that "e" and "i" are the warts for primes 11 and 23, respectively.

Edo
generator
Eigenmonzo
(unchanged-interval)
*
Generator (¢) Comments
9\28 385.7143 28ei val
11/9 386.3137 -1/4 vishdel comma
5/4 386.8520 Untempered tuning, lower bound of 5-odd-limit diamond tradeoff
10\31 387.0968 Lower bound of 2.3.5.23-subgroup 25-odd-limit diamond monotone
23/22 387.1739
375/256 387.3542 1/11-comma
41\127 387.4016 127e val
11/6 387.4469
75/64 387.4582 1/10-comma
31\96 387.5000
11/8 387.5659
52\161 387.5776
15/8 387.5854 1/9-comma
73\226 387.6106
11/10 387.6318
45/32 387.6602 2/17-comma
21\65 387.6923
23/12 387.7199
23/16 387.7338
3/2 387.7444 1/8-comma
95\294 387.7551 294e val
74\229 387.7729 229e val
53\164 387.8049 164e val
23/18 387.8178 1/2 S24
85\263 387.8327 263ee val
9/5 387.8393 2/15-comma
23/20 387.8431
32\99 387.8788 99e val
75\232 387.9310 232eei val
5/3 387.9490 1/7-comma, upper bound of 5-odd-limit diamond tradeoff
43\133 387.9699 133e val
25/23 387.9706
23/15 388.0011
54\167 388.0240 167eei val
25/24 388.2213 1/6-comma, upper bound of 2.3.5.23-subgroup 25-odd-limit diamond tradeoff
11\34 388.2353
125/96 388.6028 1/5-comma
23\71 388.7324 71eei val
625/384 389.1750 1/4-comma
12\37 389.1892 37eei val
1\3 400.0000 Upper bound of 2.3.5.23-subgroup 25-odd-limit diamond monotone

* besides the octave

Other tunings

  • DKW (2.3.5): ~2 = 1\1, ~5/4 = 387.8015
  • 5-odd-limit minimax: ~2 = 1\1, ~5/4 = 387.7444 (eigenmonzo 3/2 aka 1/8-comma, generator = 61/8)

Music

Chris Vaisvil
  • Ancient Stardust (2013) – blog | play – Würschmidt[13] in 5-odd-limit minimax tuning
Jake Freivald
  • Extrospection (2013) – play | SoundCloud – Würschmidt[16] in 31edo tuning.