231edo: Difference between revisions

Wikispaces>FREEZE
No edit summary
ArrowHead294 (talk | contribs)
mNo edit summary
 
(24 intermediate revisions by 7 users not shown)
Line 1: Line 1:
The ''231 equal temperament'' divides the octave into 231 equal parts of 5.195 cents each. In the 5-limit it tempers out the kleisma, 15625/15552, and in the 7-limit 1029/1024, so that it supports [[Kleismic_family#Tritikleismic|tritikleismic temperament]], and in fact provides the [[Optimal_patent_val|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.
{{Infobox ET}}
[[Category:tritikleismic]]
{{ED intro}}
 
== Theory ==
In the 5-limit, 231et [[tempering out|tempers out]] the [[kleisma]], 15625/15552, and in the 7-limit [[1029/1024]], so that it [[support]]s 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 {{nowrap|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 ===
{{Harmonics in equal|231}}
 
=== Subsets and supersets ===
231 = 3 × 7 × 11, with subset edos {{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 ==
{| class="wikitable center-4 center-5 center-6"
|-
! rowspan="2" | [[Subgroup]]
! rowspan="2" | [[Comma list]]
! rowspan="2" | [[Mapping]]
! rowspan="2" | Optimal<br />8ve stretch (¢)
! colspan="2" | Tuning error
|-
! [[TE error|Absolute]] (¢)
! [[TE simple badness|Relative]] (%)
|-
| 2.3.5
| 15625/15552, {{monzo| -64 36 3 }}
| {{mapping| 231 366 536 }}
| +0.410
| 0.334
| 6.43
|-
| 2.3.5.7
| 1029/1024, 15625/15552, 823543/820125
| {{mapping| 231 366 536 648 }}
| +0.539
| 0.365
| 7.01
|-
| 2.3.5.7.11
| 385/384, 441/440, 4000/3993, 823543/820125
| {{mapping| 231 366 536 648 799 }}
| +0.469
| 0.354
| 6.81
|}
 
=== Rank-2 temperaments ===
{| class="wikitable center-all left-5"
|+ style="font-size: 105%;" | Table of rank-2 temperaments by generator
|-
! Periods<br />per 8ve
! Generator*
! Cents*
! Associated<br />ratio*
! Temperaments
|-
| 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<br />(16\231)
| 316.88<br />(83.12)
| 6/5<br />(21/20)
| [[Tritikleismic]]
|}
<nowiki />* [[Normal lists|Octave-reduced form]], reduced to the first half-octave, and [[Normal lists|minimal form]] in parentheses if distinct
 
== Music ==
; [[Mercury Amalgam]]
* [https://www.youtube.com/watch?v=-bgUQ5BYnqM ''Sins of Stoicism''] (Demo Version, March 2022)
 
[[Category:Listen]]
[[Category:Tritikleismic]]