742edo: Difference between revisions
i'll fill the optimal stretch and stuff later once i have time |
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{{Infobox ET | {{Infobox ET}} | ||
{{ED intro}} | |||
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{{ | |||
== Theory == | == Theory == | ||
742edo is a very strong 19-limit system and a [[ | 742edo is a very strong 19-limit system and a [[zeta peak edo]], and is [[consistency|distinctly consistent]] in the [[21-odd-limit]]. As an equal temperament, it [[tempering out|tempers out]] the [[vishnuzma]] and the fortune comma in the 5-limit, [[support]]ing [[vishnu]] and [[fortune]]; [[2401/2400]] in the 7-limit, [[9801/9800]] in the 11-limit, [[4096/4095]], [[6656/6655]], [[10648/10647]] in the 13-limit, [[1701/1700]], [[2058/2057]], [[2601/2600]], [[4914/4913]], [[5832/5831]] in the 17-limit, 2376/2375, 2432/2431, 2926/2925, 3136/3135, 4200/4199, 5776/5775, 5929/5928, 5985/5984, 6860/6859 in the 19-limit. | ||
742 = | === Prime harmonics === | ||
{{Harmonics in equal|742|columns=11}} | |||
{{Harmonics in equal|742|columns=11|start=12|collapsed=1|title=Approximation of prime harmonics in 742edo (continued)}} | |||
=== | === Subsets and supersets === | ||
{{ | Since 742 factors into 2 × 7 × 53, 742edo has subset edos {{EDOs| 2, 7, 14, 53, 106, and 371 }}, of which [[7edo]], [[14edo]] and [[53edo]] are very notable. It supports [[silicon]] ({{nowrap|224 & 518}}) with 14 periods per octave in the 13-limit, and [[iodine]] ({{nowrap|159& 583f}}) with 53 periods per octave in the 17-limit. | ||
== Regular temperament properties == | == Regular temperament properties == | ||
{| class="wikitable center-4 center-5 center-6" | {| class="wikitable center-4 center-5 center-6" | ||
|- | |- | ||
![[TE error|Absolute]] (¢) | ! rowspan="2" | [[Subgroup]] | ||
![[TE simple badness|Relative]] (%) | ! 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 | |||
| {{Monzo| 23 6 -14 }}, {{monzo| -84 53 }} | |||
| {{Mapping| 742 1176 1723 }} | |||
| −0.0157 | |||
| 0.0555 | |||
| 3.43 | |||
|- | |||
| 2.3.5.7 | |||
| 2401/2400, 14348907/14336000, {{monzo| 23 6 -14 }} | |||
| {{Mapping| 742 1176 1723 2083 }} | |||
| −0.0035 | |||
| 0.0525 | |||
| 3.24 | |||
|- | |||
| 2.3.5.7.11 | |||
| 2401/2400, 9801/9800, 172032/171875, 1240029/1239040 | |||
| {{Mapping| 742 1176 1723 2083 2567 }} | |||
| −0.0123 | |||
| 0.0501 | |||
| 3.10 | |||
|- | |- | ||
|2.3.5 | | 2.3.5.7.11.13 | ||
| | | 2401/2400, 4096/4095, 6656/6655, 9801/9800, 39366/39325 | ||
| | | {{Mapping| 742 1176 1723 2083 2567 2746 }} | ||
| | | −0.0302 | ||
| | | 0.0608 | ||
| | | 3.76 | ||
|- | |- | ||
|2.3.5.7 | | 2.3.5.7.11.13.17 | ||
|2401/2400, | | 1701/1700, 2058/2057, 2401/2400, 2601/2600, 4096/4095, 6656/6655 | ||
| | | {{Mapping| 742 1176 1723 2083 2567 2746 3033 }} | ||
| | | −0.0317 | ||
| | | 0.0564 | ||
| | | 3.49 | ||
|- | |- | ||
|2.3.5.7.11 | | 2.3.5.7.11.13.17.19 | ||
| | | 1701/1700, 2058/2057, 2376/2375, 2401/2400, 2432/2431, 2601/2600, 3213/3211 | ||
| | | {{Mapping| 742 1176 1723 2083 2567 2746 3033 3152 }} | ||
| | | −0.0295 | ||
| | | 0.0531 | ||
| | | 3.28 | ||
|- | |- | ||
|2.3.5.7.11.13 | | 2.3.5.7.11.13.17.19.23 | ||
| | | 1197/1196, 1496/1495, 1701/1700, 2025/2024, 2058/2057, 2401/2400, 2601/2600, 3213/3211 | ||
| | | {{Mapping| 742 1176 1723 2083 2567 2746 3033 3152 3357 }} (742i) | ||
| | | −0.0468 | ||
| | | 0.0699 | ||
| | | 4.32 | ||
|} | |} | ||
* 742et has a lower 19-limit [[Tenney-Euclidean temperament measures #TE simple badness|relative error]] than any previous equal temperaments. It is only bettered by [[935edo|935]] in terms of absolute error, and by [[1178edo|1178]] in terms of relative error. | |||
* 742et (742i val) is also notable in the 17- and 23-limit, where it has lower absolute errors than any previous equal temperaments. In the 17-limit it beats [[581edo|581]] and is bettered by [[764edo|764]]; in the 23-limit it beats [[718edo|718]] and is bettered by [[814edo|814]]. | |||
=== Rank-2 temperaments === | === Rank-2 temperaments === | ||
{| class="wikitable center-all left-5" | {| class="wikitable center-all left-5" | ||
! Periods<br>per | |+ style="font-size: 105%;" | Table of rank-2 temperaments by generator | ||
! Generator | |- | ||
! Cents | ! Periods<br>per 8ve | ||
! Associated<br> | ! Generator* | ||
! Cents* | |||
! Associated<br>ratio* | |||
! Temperaments | ! Temperaments | ||
|- | |- | ||
| Line 70: | Line 91: | ||
| 8388608/7381125 | | 8388608/7381125 | ||
| [[Fortune]] | | [[Fortune]] | ||
|- | |||
| 1 | |||
| 243\742 | |||
| 392.992 | |||
| 2744/2187 | |||
| [[Emmthird]] (7-limit) | |||
|- | |||
| 1 | |||
| 303\742 | |||
| 490.026 | |||
| 896/675 | |||
| [[Surmarvelpyth]] | |||
|- | |- | ||
| 2 | | 2 | ||
| Line 95: | Line 128: | ||
| [[Iodine]] | | [[Iodine]] | ||
|} | |} | ||
<nowiki/>* [[Normal forms #Equave-reduced-generator form|Octave-reduced form]], reduced to the first half-octave, and [[normal forms #Minimal-generator form|minimal form]] in parentheses if distinct | |||
[ | == Scales == | ||
* Silicon[28]: 10 43 10 43 10 43 10 43 10 43 10 43 10 43 10 43 10 43 10 43 10 43 10 43 10 43 10 43 | |||
Latest revision as of 22:24, 25 April 2026
| ← 741edo | 742edo | 743edo → |
742 equal divisions of the octave (abbreviated 742edo or 742ed2), also called 742-tone equal temperament (742tet) or 742 equal temperament (742et) when viewed under a regular temperament perspective, is the tuning system that divides the octave into 742 equal parts of about 1.62 ¢ each. Each step represents a frequency ratio of 21/742, or the 742nd root of 2.
Theory
742edo is a very strong 19-limit system and a zeta peak edo, and is distinctly consistent in the 21-odd-limit. As an equal temperament, it tempers out the vishnuzma and the fortune comma in the 5-limit, supporting vishnu and fortune; 2401/2400 in the 7-limit, 9801/9800 in the 11-limit, 4096/4095, 6656/6655, 10648/10647 in the 13-limit, 1701/1700, 2058/2057, 2601/2600, 4914/4913, 5832/5831 in the 17-limit, 2376/2375, 2432/2431, 2926/2925, 3136/3135, 4200/4199, 5776/5775, 5929/5928, 5985/5984, 6860/6859 in the 19-limit.
Prime harmonics
| Harmonic | 2 | 3 | 5 | 7 | 11 | 13 | 17 | 19 | 23 | 29 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Error | Absolute (¢) | +0.000 | -0.068 | +0.209 | -0.093 | +0.165 | +0.443 | +0.166 | +0.061 | -0.781 | +0.611 | -0.022 |
| Relative (%) | +0.0 | -4.2 | +12.9 | -5.7 | +10.2 | +27.4 | +10.3 | +3.8 | -48.3 | +37.8 | -1.4 | |
| Steps (reduced) |
742 (0) |
1176 (434) |
1723 (239) |
2083 (599) |
2567 (341) |
2746 (520) |
3033 (65) |
3152 (184) |
3356 (388) |
3605 (637) |
3676 (708) | |
| Harmonic | 37 | 41 | 43 | 47 | 53 | 59 | 61 | 67 | 71 | 73 | 79 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Error | Absolute (¢) | -0.670 | -0.491 | -0.466 | +0.801 | -0.189 | +0.128 | +0.635 | -0.062 | -0.182 | +0.243 | -0.655 |
| Relative (%) | -41.4 | -30.4 | -28.8 | +49.5 | -11.7 | +7.9 | +39.3 | -3.8 | -11.2 | +15.0 | -40.5 | |
| Steps (reduced) |
3865 (155) |
3975 (265) |
4026 (316) |
4122 (412) |
4250 (540) |
4365 (655) |
4401 (691) |
4501 (49) |
4563 (111) |
4593 (141) |
4677 (225) | |
Subsets and supersets
Since 742 factors into 2 × 7 × 53, 742edo has subset edos 2, 7, 14, 53, 106, and 371, of which 7edo, 14edo and 53edo are very notable. It supports silicon (224 & 518) with 14 periods per octave in the 13-limit, and iodine (159& 583f) with 53 periods per octave in the 17-limit.
Regular temperament properties
| Subgroup | Comma list | Mapping | Optimal 8ve stretch (¢) |
Tuning error | |
|---|---|---|---|---|---|
| Absolute (¢) | Relative (%) | ||||
| 2.3.5 | [23 6 -14⟩, [-84 53⟩ | [⟨742 1176 1723]] | −0.0157 | 0.0555 | 3.43 |
| 2.3.5.7 | 2401/2400, 14348907/14336000, [23 6 -14⟩ | [⟨742 1176 1723 2083]] | −0.0035 | 0.0525 | 3.24 |
| 2.3.5.7.11 | 2401/2400, 9801/9800, 172032/171875, 1240029/1239040 | [⟨742 1176 1723 2083 2567]] | −0.0123 | 0.0501 | 3.10 |
| 2.3.5.7.11.13 | 2401/2400, 4096/4095, 6656/6655, 9801/9800, 39366/39325 | [⟨742 1176 1723 2083 2567 2746]] | −0.0302 | 0.0608 | 3.76 |
| 2.3.5.7.11.13.17 | 1701/1700, 2058/2057, 2401/2400, 2601/2600, 4096/4095, 6656/6655 | [⟨742 1176 1723 2083 2567 2746 3033]] | −0.0317 | 0.0564 | 3.49 |
| 2.3.5.7.11.13.17.19 | 1701/1700, 2058/2057, 2376/2375, 2401/2400, 2432/2431, 2601/2600, 3213/3211 | [⟨742 1176 1723 2083 2567 2746 3033 3152]] | −0.0295 | 0.0531 | 3.28 |
| 2.3.5.7.11.13.17.19.23 | 1197/1196, 1496/1495, 1701/1700, 2025/2024, 2058/2057, 2401/2400, 2601/2600, 3213/3211 | [⟨742 1176 1723 2083 2567 2746 3033 3152 3357]] (742i) | −0.0468 | 0.0699 | 4.32 |
- 742et has a lower 19-limit relative error than any previous equal temperaments. It is only bettered by 935 in terms of absolute error, and by 1178 in terms of relative error.
- 742et (742i val) is also notable in the 17- and 23-limit, where it has lower absolute errors than any previous equal temperaments. In the 17-limit it beats 581 and is bettered by 764; in the 23-limit it beats 718 and is bettered by 814.
Rank-2 temperaments
| Periods per 8ve |
Generator* | Cents* | Associated ratio* |
Temperaments |
|---|---|---|---|---|
| 1 | 137\742 | 221.563 | 8388608/7381125 | Fortune |
| 1 | 243\742 | 392.992 | 2744/2187 | Emmthird (7-limit) |
| 1 | 303\742 | 490.026 | 896/675 | Surmarvelpyth |
| 2 | 44\742 | 71.159 | 25/24 | Vishnu |
| 14 | 434\742 (10\742) |
701.886 (16.173) |
3/2 (105/104) |
Silicon |
| 53 | 239\742 (1\742) |
386.523 (1.617) |
5/4 (32805/32768) |
Mercator |
| 53 | 565\742 (5\742) |
913.746 (8.086) |
441/260 (196/195) |
Iodine |
* Octave-reduced form, reduced to the first half-octave, and minimal form in parentheses if distinct
Scales
- Silicon[28]: 10 43 10 43 10 43 10 43 10 43 10 43 10 43 10 43 10 43 10 43 10 43 10 43 10 43 10 43