251edo: Difference between revisions
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== Theory == | == Theory == | ||
251et [[tempering out|tempers out]] 1600000/1594323 ([[amity comma]]) and {{monzo| 49 -6 -17 }} ([[maquila comma]]) in the 5-limit; [[4375/4374]], [[5120/5103]], and 40500000/40353607 in the 7-limit, [[support]]ing [[amity]], [[supermajor]], and [[acrokleismic]]. | 251et [[tempering out|tempers out]] 1600000/1594323 ([[amity comma]]) and {{monzo| 49 -6 -17 }} ([[maquila comma]]) in the 5-limit; [[4375/4374]], [[5120/5103]], and 40500000/40353607 in the 7-limit, [[support]]ing [[amity]], [[supermajor (temperament)|supermajor]], and [[acrokleismic]]. | ||
Using the [[patent val]] {{val| 251 398 583 705 '''868''' }}, it tempers out 1331/1323, 1375/1372, 16896/16807, and 24057/24010 in the 11-limit; [[352/351]], [[676/675]], [[847/845]], and [[1573/1568]] in the 13-limit. | Using the [[patent val]] {{val| 251 398 583 705 '''868''' }}, it tempers out 1331/1323, 1375/1372, 16896/16807, and 24057/24010 in the 11-limit; [[352/351]], [[676/675]], [[847/845]], and [[1573/1568]] in the 13-limit. | ||
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! rowspan="2" | [[Comma list]] | ! rowspan="2" | [[Comma list]] | ||
! rowspan="2" | [[Mapping]] | ! rowspan="2" | [[Mapping]] | ||
! rowspan="2" | Optimal<br | ! rowspan="2" | Optimal<br>8ve stretch (¢) | ||
! colspan="2" | Tuning error | ! colspan="2" | Tuning error | ||
|- | |- | ||
| Line 28: | Line 28: | ||
|- | |- | ||
| 2.3 | | 2.3 | ||
| {{ | | {{Monzo| 398 -251 }} | ||
| {{ | | {{Mapping| 251 398 }} | ||
| −0.2630 | | −0.2630 | ||
| 0.2630 | | 0.2630 | ||
| Line 35: | Line 35: | ||
|- | |- | ||
| 2.3.5 | | 2.3.5 | ||
| {{ | | {{Monzo| 9 -13 5 }}, {{monzo| 49 -6 -17 }} | ||
| {{ | | {{Mapping| 251 398 583 }} | ||
| −0.3099 | | −0.3099 | ||
| 0.2247 | | 0.2247 | ||
| Line 43: | Line 43: | ||
| 2.3.5.7 | | 2.3.5.7 | ||
| 4375/4374, 5120/5103, 40500000/40353607 | | 4375/4374, 5120/5103, 40500000/40353607 | ||
| {{ | | {{Mapping| 251 398 583 705 }} | ||
| −0.3830 | | −0.3830 | ||
| 0.2322 | | 0.2322 | ||
| Line 53: | Line 53: | ||
|+ style="font-size: 105%;" | Table of rank-2 temperaments by generator | |+ style="font-size: 105%;" | Table of rank-2 temperaments by generator | ||
|- | |- | ||
! Periods<br | ! Periods<br>per 8ve | ||
! Generator* | ! Generator* | ||
! Cents* | ! Cents* | ||
! Associated<br | ! Associated<br>ratio* | ||
! Temperaments | ! Temperaments | ||
|- | |- | ||
| Line 75: | Line 75: | ||
| 435.06 | | 435.06 | ||
| 9/7 | | 9/7 | ||
| [[Supermajor]] | | [[Supermajor (temperament)|Supermajor]] | ||
|- | |- | ||
| 1 | | 1 | ||
| Line 89: | Line 89: | ||
| [[Maquila]] | | [[Maquila]] | ||
|} | |} | ||
<nowiki />* [[Normal | <nowiki/>* [[Normal forms|Octave-reduced form]], reduced to the first half-octave, and [[Normal forms|minimal form]] in parentheses if distinct | ||
== Music == | == Music == | ||
Revision as of 13:28, 27 October 2025
| ← 250edo | 251edo | 252edo → |
251 equal divisions of the octave (abbreviated 251edo or 251ed2), also called 251-tone equal temperament (251tet) or 251 equal temperament (251et) when viewed under a regular temperament perspective, is the tuning system that divides the octave into 251 equal parts of about 4.78 ¢ each. Each step represents a frequency ratio of 21/251, or the 251st root of 2.
Theory
251et tempers out 1600000/1594323 (amity comma) and [49 -6 -17⟩ (maquila comma) in the 5-limit; 4375/4374, 5120/5103, and 40500000/40353607 in the 7-limit, supporting amity, supermajor, and acrokleismic.
Using the patent val ⟨251 398 583 705 868], it tempers out 1331/1323, 1375/1372, 16896/16807, and 24057/24010 in the 11-limit; 352/351, 676/675, 847/845, and 1573/1568 in the 13-limit.
Using the 251e val ⟨251 398 583 705 869], it tempers out 540/539, 5632/5625, 6250/6237, and 12005/11979 in the 11-limit; 364/363, 676/675, 1716/1715, and 3584/3575 in the 13-limit.
Odd harmonics
| Harmonic | 3 | 5 | 7 | 9 | 11 | 13 | 15 | 17 | 19 | 21 | 23 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Error | Absolute (¢) | +0.83 | +0.94 | +1.69 | +1.67 | -1.52 | +0.91 | +1.77 | +0.22 | -1.10 | -2.26 | -1.98 |
| Relative (%) | +17.4 | +19.6 | +35.4 | +34.9 | -31.7 | +19.0 | +37.0 | +4.7 | -23.0 | -47.2 | -41.4 | |
| Steps (reduced) |
398 (147) |
583 (81) |
705 (203) |
796 (43) |
868 (115) |
929 (176) |
981 (228) |
1026 (22) |
1066 (62) |
1102 (98) |
1135 (131) | |
Subsets and supersets
251edo is the 54th prime edo.
Regular temperament properties
| Subgroup | Comma list | Mapping | Optimal 8ve stretch (¢) |
Tuning error | |
|---|---|---|---|---|---|
| Absolute (¢) | Relative (%) | ||||
| 2.3 | [398 -251⟩ | [⟨251 398]] | −0.2630 | 0.2630 | 5.50 |
| 2.3.5 | [9 -13 5⟩, [49 -6 -17⟩ | [⟨251 398 583]] | −0.3099 | 0.2247 | 4.70 |
| 2.3.5.7 | 4375/4374, 5120/5103, 40500000/40353607 | [⟨251 398 583 705]] | −0.3830 | 0.2322 | 4.86 |
Rank-2 temperaments
| Periods per 8ve |
Generator* | Cents* | Associated ratio* |
Temperaments |
|---|---|---|---|---|
| 1 | 66\251 | 315.54 | 6/5 | Acrokleismic |
| 1 | 71\251 | 339.44 | 243/200 | Amity |
| 1 | 91\251 | 435.06 | 9/7 | Supermajor |
| 1 | 96\251 | 458.96 | 125/96 | Majvam |
| 1 | 112\251 | 535.46 | 512/375 | Maquila |
* Octave-reduced form, reduced to the first half-octave, and minimal form in parentheses if distinct