← 230edo 231edo 232edo →
Prime factorization 3 × 7 × 11
Step size 5.19481 ¢ 
Fifth 135\231 (701.299 ¢) (→ 45\77)
Semitones (A1:m2) 21:18 (109.1 ¢ : 93.51 ¢)
Consistency limit 11
Distinct consistency limit 11

Template:EDO intro

Theory

In the 5-limit, 231et tempers out the kleisma, 15625/15552, and in the 7-limit 1029/1024, so that it supports the tritikleismic temperament, and in fact provides the optimal patent val. In the 11-limit it tempers out 385/384, 441/440 and 4000/3993, leading to 11-limit tritikleismic for which it also gives the optimal patent val.

231 years is the number of years in a 41 out of 231 leap week cycle, which corresponds to a 41 & 149 temperament tempering out 132055/131072, 166375/165888, and 2460375/2458624. This type of solar calendar leap rule scale may actually be of more use to harmony, since a 41 note subset mimics 41edo, a rather useful edo harmonically, and it preserves the simple commas mentioned above.

Odd harmonics

Approximation of odd harmonics in 231edo
Harmonic 3 5 7 9 11 13 15 17 19 21 23
Error Absolute (¢) -0.66 -1.90 -2.59 -1.31 -0.67 +1.03 -2.55 -1.06 -1.41 +1.95 +0.30
Relative (%) -12.6 -36.5 -49.9 -25.3 -12.9 +19.8 -49.2 -20.4 -27.1 +37.5 +5.7
Steps
(reduced)
366
(135)
536
(74)
648
(186)
732
(39)
799
(106)
855
(162)
902
(209)
944
(20)
981
(57)
1015
(91)
1045
(121)

Subsets and supersets

231 = 3 × 7 × 11, with subset edos 3, 7, 11, 21, 33, and 77. Since it contains 77edo, it can be used for playing such a tuning of the Carlos Alpha scale.

Regular temperament properties

Template:Comma basis begin |- | 2.3.5 | 15625/15552, [-64 36 3 | [231 366 536]] | 0.410 | 0.334 | 6.43 |- | 2.3.5.7 | 1029/1024, 15625/15552, 823543/820125 | [231 366 536 648]] | 0.539 | 0.365 | 7.01 |- | 2.3.5.7.11 | 385/384, 441/440, 4000/3993, 823543/820125 | [231 366 536 648 799]] | 0.469 | 0.354 | 6.81 Template:Comma basis end

Rank-2 temperaments

Template:Rank-2 begin |- | 1 | 26\231 | 135.06 | 27/25 | Superlimmal |- | 1 | 27\231 | 140.26 | 243/224 | Septichrome |- | 1 | 45\231 | 233.77 | 8/7 | Slendric |- | 1 | 61\231 | 316.88 | 6/5 | Hanson |- | 1 | 62\231 | 322.08 | 135/112 | Dee leap week |- | 1 | 73\231 | 379.22 | 56/45 | Marthirds |- | 3 | 61\231
(16\231) | 316.88
(83.12) | 6/5
(21/20) | Tritikleismic Template:Rank-2 end Template:Orf

Music

Mercury Amalgam