764edo: Difference between revisions
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=== Prime harmonics === | === Prime harmonics === | ||
{{Harmonics in equal|764|columns= | {{Harmonics in equal|764|columns=11}} | ||
{{Harmonics in equal|764|columns=11|start=12|collapsed=true|title=Approximation of prime harmonics in 764edo (continued)}} | |||
=== Subsets and supersets === | === Subsets and supersets === | ||
Since 764 factors into {{ | Since 764 factors into primes as {{nowrap| 2<sup>2</sup> × 191 }}, 764edo has subset edos 2, 4, 191, and 382. In addition, one step of 764edo is exactly 22 [[jinn]]s ([[16808edo|22\16808]]). | ||
== Regular temperament properties == | == Regular temperament properties == | ||
| Line 19: | Line 20: | ||
! 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 26: | Line 27: | ||
|- | |- | ||
| 2.3 | | 2.3 | ||
| {{ | | {{Monzo| 1211 -764 }} | ||
| {{ | | {{Mapping| 764 1211 }} | ||
| −0.0439 | | −0.0439 | ||
| 0.0439 | | 0.0439 | ||
| Line 33: | Line 34: | ||
|- | |- | ||
| 2.3.5 | | 2.3.5 | ||
| {{ | | {{Monzo| 38 -2 -15 }}, {{monzo| 25 -48 22 }} | ||
| {{ | | {{Mapping| 764 1211 1774 }} | ||
| −0.0399 | | −0.0399 | ||
| 0.0363 | | 0.0363 | ||
| Line 41: | Line 42: | ||
| 2.3.5.7 | | 2.3.5.7 | ||
| 4375/4374, 52734375/52706752, {{monzo| 31 -6 -2 -6 }} | | 4375/4374, 52734375/52706752, {{monzo| 31 -6 -2 -6 }} | ||
| {{ | | {{Mapping| 764 1211 1774 2145 }} | ||
| −0.0552 | | −0.0552 | ||
| 0.0412 | | 0.0412 | ||
| Line 48: | Line 49: | ||
| 2.3.5.7.11 | | 2.3.5.7.11 | ||
| 3025/3024, 4375/4374, 131072/130977, 35156250/35153041 | | 3025/3024, 4375/4374, 131072/130977, 35156250/35153041 | ||
| {{ | | {{Mapping| 764 1211 1774 2145 2643 }} | ||
| −0.0436 | | −0.0436 | ||
| 0.0435 | | 0.0435 | ||
| Line 55: | Line 56: | ||
| 2.3.5.7.11.13 | | 2.3.5.7.11.13 | ||
| 1716/1715, 2080/2079, 3025/3024, 4096/4095, 10549994/10546875 | | 1716/1715, 2080/2079, 3025/3024, 4096/4095, 10549994/10546875 | ||
| {{ | | {{Mapping| 764 1211 1774 2145 2643 2827 }} | ||
| −0.0267 | | −0.0267 | ||
| 0.0548 | | 0.0548 | ||
| Line 62: | Line 63: | ||
| 2.3.5.7.11.13.17 | | 2.3.5.7.11.13.17 | ||
| 1716/1715, 2080/2079, 2431/2430, 2500/2499, 4096/4095, 4914/4913 | | 1716/1715, 2080/2079, 2431/2430, 2500/2499, 4096/4095, 4914/4913 | ||
| {{ | | {{Mapping| 764 1211 1774 2145 2643 2827 3123 }} | ||
| −0.0327 | | −0.0327 | ||
| 0.0528 | | 0.0528 | ||
| Line 69: | Line 70: | ||
| 2.3.5.7.11.13.17.23 | | 2.3.5.7.11.13.17.23 | ||
| 1716/1715, 2080/2079, 2024/2023, 2431/2430, 2500/2499, 3520/3519, 4096/4095 | | 1716/1715, 2080/2079, 2024/2023, 2431/2430, 2500/2499, 3520/3519, 4096/4095 | ||
| {{ | | {{Mapping| 764 1211 1774 2145 2643 2827 3123 3456 }} | ||
| −0.0286 | | −0.0286 | ||
| 0.0506 | | 0.0506 | ||
| Line 81: | Line 82: | ||
|+ 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 97: | Line 98: | ||
| 435.08 | | 435.08 | ||
| 9/7 | | 9/7 | ||
| [[Supermajor]] | | [[Supermajor (temperament)|Supermajor]] | ||
|- | |- | ||
| 2 | | 2 | ||
| Line 106: | Line 107: | ||
|- | |- | ||
| 2 | | 2 | ||
| 277\764<br | | 277\764<br>(105\764) | ||
| 435.08<br | | 435.08<br>(164.92) | ||
| 9/7<br | | 9/7<br>(11/10) | ||
| [[Semisupermajor]] | | [[Semisupermajor]] | ||
|} | |} | ||
<nowiki />* [[Normal | <nowiki/>* [[Normal forms|Octave-reduced form]], reduced to the first half-octave, and [[Normal forms|minimal form]] in parentheses if distinct | ||
[[Category:Abigail]] | [[Category:Abigail]] | ||
Revision as of 13:35, 27 October 2025
| ← 763edo | 764edo | 765edo → |
764 equal divisions of the octave (abbreviated 764edo or 764ed2), also called 764-tone equal temperament (764tet) or 764 equal temperament (764et) when viewed under a regular temperament perspective, is the tuning system that divides the octave into 764 equal parts of about 1.57 ¢ each. Each step represents a frequency ratio of 21/764, or the 764th root of 2.
Theory
764edo is a very strong 17-limit system, consistent to the 17-odd-limit or the no-19 no-29 41-odd-limit. It is the fourteenth zeta integral edo. In the 5-limit it tempers out the hemithirds comma, [38 -2 -15⟩; in the 7-limit 4375/4374; in the 11-limit 3025/3024 and 9801/9800; in the 13-limit 1716/1715, 2080/2079, 4096/4095, 4225/4224, 6656/6655 and 10648/10647; and in the 17-limit 2431/2430, 2500/2499, 4914/4913 and 5832/5831. It provides the optimal patent val for the abigail temperament in the 11-limit.
In higher limits, it is a strong no-19 and no-29 37-limit tuning, and an exceptional 2.11.23.31.37 subgroup system, with errors less than 2%.
Prime harmonics
| Harmonic | 2 | 3 | 5 | 7 | 11 | 13 | 17 | 19 | 23 | 29 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Error | Absolute (¢) | +0.000 | +0.139 | +0.074 | +0.284 | -0.009 | -0.214 | +0.280 | -0.654 | -0.002 | -0.781 | -0.009 |
| Relative (%) | +0.0 | +8.9 | +4.7 | +18.1 | -0.6 | -13.6 | +17.8 | -41.7 | -0.1 | -49.7 | -0.6 | |
| Steps (reduced) |
764 (0) |
1211 (447) |
1774 (246) |
2145 (617) |
2643 (351) |
2827 (535) |
3123 (67) |
3245 (189) |
3456 (400) |
3711 (655) |
3785 (729) | |
| Harmonic | 37 | 41 | 43 | 47 | 53 | 59 | 61 | 67 | 71 | 73 | 79 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Error | Absolute (¢) | -0.035 | -0.267 | +0.524 | +0.462 | -0.206 | -0.533 | -0.131 | -0.773 | -0.639 | -0.041 | -0.139 |
| Relative (%) | -2.2 | -17.0 | +33.4 | +29.4 | -13.1 | -33.9 | -8.3 | -49.2 | -40.7 | -2.6 | -8.8 | |
| Steps (reduced) |
3980 (160) |
4093 (273) |
4146 (326) |
4244 (424) |
4376 (556) |
4494 (674) |
4531 (711) |
4634 (50) |
4698 (114) |
4729 (145) |
4816 (232) | |
Subsets and supersets
Since 764 factors into primes as 22 × 191, 764edo has subset edos 2, 4, 191, and 382. In addition, one step of 764edo is exactly 22 jinns (22\16808).
Regular temperament properties
| Subgroup | Comma list | Mapping | Optimal 8ve stretch (¢) |
Tuning error | |
|---|---|---|---|---|---|
| Absolute (¢) | Relative (%) | ||||
| 2.3 | [1211 -764⟩ | [⟨764 1211]] | −0.0439 | 0.0439 | 2.80 |
| 2.3.5 | [38 -2 -15⟩, [25 -48 22⟩ | [⟨764 1211 1774]] | −0.0399 | 0.0363 | 2.31 |
| 2.3.5.7 | 4375/4374, 52734375/52706752, [31 -6 -2 -6⟩ | [⟨764 1211 1774 2145]] | −0.0552 | 0.0412 | 2.62 |
| 2.3.5.7.11 | 3025/3024, 4375/4374, 131072/130977, 35156250/35153041 | [⟨764 1211 1774 2145 2643]] | −0.0436 | 0.0435 | 2.77 |
| 2.3.5.7.11.13 | 1716/1715, 2080/2079, 3025/3024, 4096/4095, 10549994/10546875 | [⟨764 1211 1774 2145 2643 2827]] | −0.0267 | 0.0548 | 3.49 |
| 2.3.5.7.11.13.17 | 1716/1715, 2080/2079, 2431/2430, 2500/2499, 4096/4095, 4914/4913 | [⟨764 1211 1774 2145 2643 2827 3123]] | −0.0327 | 0.0528 | 3.36 |
| 2.3.5.7.11.13.17.23 | 1716/1715, 2080/2079, 2024/2023, 2431/2430, 2500/2499, 3520/3519, 4096/4095 | [⟨764 1211 1774 2145 2643 2827 3123 3456]] | −0.0286 | 0.0506 | 3.22 |
- 764et has lower absolute errors than any previous equal temperaments in the 13- and 17-limit. In the 13-limit it beats 684 and is only bettered by 935. In the 17-limit it beats 742 and is only bettered by 814.
- It is best at the no-19 23-limit, where it has a lower relative error than any previous equal temperaments, past 494 and before 1578.
Rank-2 temperaments
| Periods per 8ve |
Generator* | Cents* | Associated ratio* |
Temperaments |
|---|---|---|---|---|
| 1 | 123\764 | 193.19 | 262144/234375 | Lunatic (7-limit) |
| 1 | 277\764 | 435.08 | 9/7 | Supermajor |
| 2 | 133\764 | 208.90 | 44/39 | Abigail |
| 2 | 277\764 (105\764) |
435.08 (164.92) |
9/7 (11/10) |
Semisupermajor |
* Octave-reduced form, reduced to the first half-octave, and minimal form in parentheses if distinct