13edt: Difference between revisions
Fix weird placement of the theory section title. Various other cleanup |
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{{Infobox ET}} | {{Infobox ET}} | ||
[[File:13edt.png|thumb|alt=13edt.png|A plot of the [[ | {{ED intro}} It is best known as the equal-tempered version of the [[Bohlen–Pierce]] scale, and therefore has received by far the most attention among equal divisions of the tritave. | ||
[[File:13edt.png|thumb|alt=13edt.png|A plot of the [[Riemann zeta function#Removing primes|no-twos Z-function]], in terms of which 13edt is the fourth no-twos zeta peak [[EDT]].]] | |||
[[File:pts-3-5-7-e3-twtop.jpg|thumb|Projective tuning space of the [[3.5.7 subgroup]], showing 13edt near the center.]] | |||
== Theory == | |||
{{See also| Relationship between Bohlen-Pierce and octave-ful temperaments }} | |||
13edt provides an excellent approximation to the [[3.5.7 subgroup]], especially for its size, being comparable to [[34edo]]'s accuracy in the 5-limit. In this subgroup, it tempers out [[245/243]] and [[3125/3087]], the same commas as the rank-2 [[bohpier]] temperament. It is less impressive in higher prime limits, but makes for excellent no-twos 7-limit harmony. For higher limits, the multiples of 13 ([[26edt]], [[39edt]], and [[52edt]]) come to the fore. | |||
13edt can be described as approximately 8.202[[edo]]. This implies that each step of 13edt can be approximated by 5 steps of [[41edo]]. | 13edt can be described as approximately 8.202[[edo]]. This implies that each step of 13edt can be approximated by 5 steps of [[41edo]]. | ||
In the | In the 3.5.7 subgroup, 13edt maintains the smallest relative error of any EDT until [[258edt]] and [[271edt]], and the smallest absolute error until [[56edt]]. | ||
=== Odd harmonics === | |||
{{Harmonics in equal|13|3|1|prec=2|intervals=odd|columns=11}} | |||
{{Harmonics in equal|13|3|1|prec=2|intervals=odd|columns=12|start=12|collapsed=true|title=Approximation of odd harmonics in 13edt (continued)}} | |||
== Intervals == | == Intervals == | ||
{{Main|Intervals of BP}} | {{Main|Intervals of BP}} | ||
{| class="wikitable center- | {| class="wikitable center-all right-2 right-3" | ||
|- | |- | ||
! Steps | ! Steps | ||
! [[Cent]]s | ! [[Cent]]s | ||
! [[Hekt]]s | ! [[Hekt]]s | ||
! | ! [[4L 5s (3/1-equivalent)|Enneatonic]]<br />degree | ||
! Corresponding | ! Corresponding<br />3.5.7 subgroup<br />intervals | ||
! [[Lambda ups and downs notation|Lambda]]<br />(sLsLsLsLs, {{nowrap|E {{=}} 1/1}}) | |||
|- | |||
! [[ | | 0 | ||
| 0 | |||
| 0 | |||
| P1 | |||
| 1/1 | |||
| E | |||
|- | |- | ||
| 1 | | 1 | ||
| Line 31: | Line 40: | ||
| 100 | | 100 | ||
| A1/m2 | | A1/m2 | ||
| 27/25 | | [[49/45]] (−1.1{{c}}); [[27/25]] (+13.1{{c}}) | ||
| F | |||
| | |||
|- | |- | ||
| 2 | | 2 | ||
| Line 40: | Line 47: | ||
| 200 | | 200 | ||
| M2/d3 | | M2/d3 | ||
| 25/21 | | [[25/21]] (−9.2{{c}}) | ||
| F#, Gb | |||
| | |||
|- | |- | ||
| 3 | | 3 | ||
| Line 49: | Line 54: | ||
| 300 | | 300 | ||
| A2/P3/d4 | | A2/P3/d4 | ||
| 9/7 | | [[9/7]] (+3.8{{c}}) | ||
| G | |||
| | |||
|- | |- | ||
| 4 | | 4 | ||
| Line 58: | Line 61: | ||
| 400 | | 400 | ||
| A3/m4/d5 | | A3/m4/d5 | ||
| 7/5 | | [[7/5]] (+2.7{{c}}) | ||
| H | |||
| | |||
|- | |- | ||
| 5 | | 5 | ||
| Line 67: | Line 68: | ||
| 500 | | 500 | ||
| M4/m5 | | M4/m5 | ||
| 75/49 | | [[75/49]] (−5.4{{c}}) | ||
| | | H#, Jb | ||
|- | |- | ||
| 6 | | 6 | ||
| Line 76: | Line 75: | ||
| 600 | | 600 | ||
| A4/M5 | | A4/M5 | ||
| 5/3 | | [[5/3]] (−6.5{{c}}) | ||
| J | |||
| | |||
|- | |- | ||
| 7 | | 7 | ||
| Line 85: | Line 82: | ||
| 700 | | 700 | ||
| A5/m6/d7 | | A5/m6/d7 | ||
| 9/5 | | [[9/5]] (+6.5{{c}}) | ||
| | | A | ||
|- | |- | ||
| 8 | | 8 | ||
| Line 94: | Line 89: | ||
| 800 | | 800 | ||
| M6/m7 | | M6/m7 | ||
| 49/25 | | [[49/25]] (+5.4{{c}}) | ||
| | | A#, Bb | ||
|- | |- | ||
| 9 | | 9 | ||
| Line 103: | Line 96: | ||
| 900 | | 900 | ||
| A6/M7/d8 | | A6/M7/d8 | ||
| 15/7 | | [[15/7]] (−2.7{{c}}) | ||
| | | B | ||
|- | |- | ||
| 10 | | 10 | ||
| Line 112: | Line 103: | ||
| 1000 | | 1000 | ||
| P8/d9 | | P8/d9 | ||
| 7/3 | | [[7/3]] (−3.8{{c}}) | ||
| | | C | ||
|- | |- | ||
| 11 | | 11 | ||
| Line 121: | Line 110: | ||
| 1100 | | 1100 | ||
| A8/m9 | | A8/m9 | ||
| 63/25 | | [[63/25]] (+9.2{{c}}) | ||
| | | C#, Db | ||
|- | |- | ||
| 12 | | 12 | ||
| Line 130: | Line 117: | ||
| 1200 | | 1200 | ||
| M9/d10 | | M9/d10 | ||
| 25/9 | | [[135/49]] (+1.1{{c}}); [[25/9]] (−13.1{{c}}) | ||
| D | |||
| | |||
|- | |- | ||
| 13 | | 13 | ||
| Line 139: | Line 124: | ||
| 1300 | | 1300 | ||
| A9/P10 | | A9/P10 | ||
| 3/1 | | [[3/1]] | ||
| | | E | ||
|} | |} | ||
| Line 169: | Line 152: | ||
=== Rank-2 temperaments === | === Rank-2 temperaments === | ||
{| class="wikitable center-all right-3 left-5" | {| class="wikitable center-all right-3 left-5" | ||
|+Table of rank-2 temperaments by generator | |+ style="font-size: 105%;" | Table of rank-2 temperaments by generator | ||
! Periods<br>per tritave | |- | ||
! Generator<br>(reduced) | ! Periods<br />per tritave | ||
! Cents<br>(reduced) | ! Generator<br />(reduced) | ||
! Associated<br>ratio | ! Cents<br />(reduced) | ||
! Associated<br />ratio | |||
! Temperament | ! Temperament | ||
|- | |- | ||
| Line 200: | Line 184: | ||
| [[Canopus]] | | [[Canopus]] | ||
|- | |- | ||
|1 | | 1 | ||
|5\13 | | 5\13 | ||
|731.63 | | 731.63 | ||
|75/49 | | 75/49 | ||
| | | | ||
|- | |- | ||
| Line 212: | Line 196: | ||
| [[Arcturus]] | | [[Arcturus]] | ||
|} | |} | ||
== Music == | |||
See also: [[Bohlen–Pierce scale/Music]] | |||
; [[Bryan Deister]] | |||
* [https://www.youtube.com/shorts/dKFwJsxE3VU ''13ed3''] (2026) | |||
== See also == | == See also == | ||
| Line 220: | Line 210: | ||
* [[23ed7|23ED7]]: relative ED7 | * [[23ed7|23ED7]]: relative ED7 | ||
[[Category:Tritave]] | [[Category:Tritave]] | ||
[[Category:Macrotonal]] | [[Category:Macrotonal]] | ||
[[Category:Nonoctave]] | [[Category:Nonoctave]] | ||
[[Category: | [[Category:Bohlen–Pierce]] | ||
Latest revision as of 06:07, 12 October 2026
| ← 12edt | 13edt | 14edt → |
13 equal divisions of the tritave, perfect twelfth, or 3rd harmonic (abbreviated 13edt or 13ed3), is a nonoctave tuning system that divides the interval of 3/1 into 13 equal parts of about 146 ¢ each. Each step represents a frequency ratio of 31/13, or the 13th root of 3. It is best known as the equal-tempered version of the Bohlen–Pierce scale, and therefore has received by far the most attention among equal divisions of the tritave.


Theory
13edt provides an excellent approximation to the 3.5.7 subgroup, especially for its size, being comparable to 34edo's accuracy in the 5-limit. In this subgroup, it tempers out 245/243 and 3125/3087, the same commas as the rank-2 bohpier temperament. It is less impressive in higher prime limits, but makes for excellent no-twos 7-limit harmony. For higher limits, the multiples of 13 (26edt, 39edt, and 52edt) come to the fore.
13edt can be described as approximately 8.202edo. This implies that each step of 13edt can be approximated by 5 steps of 41edo.
In the 3.5.7 subgroup, 13edt maintains the smallest relative error of any EDT until 258edt and 271edt, and the smallest absolute error until 56edt.
Odd harmonics
| Harmonic | 3 | 5 | 7 | 9 | 11 | 13 | 15 | 17 | 19 | 21 | 23 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Error | Absolute (¢) | +0.00 | -6.53 | -3.83 | +0.00 | -54.80 | -51.40 | -6.53 | +69.39 | +23.14 | -3.83 | -15.02 |
| Relative (%) | +0.0 | -4.5 | -2.6 | +0.0 | -37.5 | -35.1 | -4.5 | +47.4 | +15.8 | -2.6 | -10.3 | |
| Steps (reduced) |
13 (0) |
19 (6) |
23 (10) |
26 (0) |
28 (2) |
30 (4) |
32 (6) |
34 (8) |
35 (9) |
36 (10) |
37 (11) | |
| Harmonic | 25 | 27 | 29 | 31 | 33 | 35 | 37 | 39 | 41 | 43 | 45 | 47 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Error | Absolute (¢) | -13.07 | +0.00 | +22.59 | +53.44 | -54.80 | -10.36 | +39.74 | -51.40 | +8.32 | +72.17 | -6.53 | +64.49 |
| Relative (%) | -8.9 | +0.0 | +15.4 | +36.5 | -37.5 | -7.1 | +27.2 | -35.1 | +5.7 | +49.3 | -4.5 | +44.1 | |
| Steps (reduced) |
38 (12) |
39 (0) |
40 (1) |
41 (2) |
41 (2) |
42 (3) |
43 (4) |
43 (4) |
44 (5) |
45 (6) |
45 (6) |
46 (7) | |
Intervals
| Steps | Cents | Hekts | Enneatonic degree |
Corresponding 3.5.7 subgroup intervals |
Lambda (sLsLsLsLs, E = 1/1) |
|---|---|---|---|---|---|
| 0 | 0 | 0 | P1 | 1/1 | E |
| 1 | 146.3 | 100 | A1/m2 | 49/45 (−1.1 ¢); 27/25 (+13.1 ¢) | F |
| 2 | 292.6 | 200 | M2/d3 | 25/21 (−9.2 ¢) | F#, Gb |
| 3 | 438.9 | 300 | A2/P3/d4 | 9/7 (+3.8 ¢) | G |
| 4 | 585.2 | 400 | A3/m4/d5 | 7/5 (+2.7 ¢) | H |
| 5 | 731.5 | 500 | M4/m5 | 75/49 (−5.4 ¢) | H#, Jb |
| 6 | 877.8 | 600 | A4/M5 | 5/3 (−6.5 ¢) | J |
| 7 | 1024.1 | 700 | A5/m6/d7 | 9/5 (+6.5 ¢) | A |
| 8 | 1170.4 | 800 | M6/m7 | 49/25 (+5.4 ¢) | A#, Bb |
| 9 | 1316.7 | 900 | A6/M7/d8 | 15/7 (−2.7 ¢) | B |
| 10 | 1463.0 | 1000 | P8/d9 | 7/3 (−3.8 ¢) | C |
| 11 | 1609.3 | 1100 | A8/m9 | 63/25 (+9.2 ¢) | C#, Db |
| 12 | 1755.7 | 1200 | M9/d10 | 135/49 (+1.1 ¢); 25/9 (−13.1 ¢) | D |
| 13 | 1902.0 | 1300 | A9/P10 | 3/1 | E |
JI approximation
Regular temperament properties
| Subgroup | Comma list | Mapping | Optimal Equave stretch (¢) |
Tuning error | |
|---|---|---|---|---|---|
| Absolute (¢) | Relative (%) | ||||
| 3.5.7 | 245/243, 3125/3087 | [⟨13 19 23]] (b13) | +1.393 | 1.150 | 0.79 |
Rank-2 temperaments
| Periods per tritave |
Generator (reduced) |
Cents (reduced) |
Associated ratio |
Temperament |
|---|---|---|---|---|
| 1 | 1\13 | 146.30 | 49/45 | Procyon |
| 1 | 2\13 | 292.61 | 25/21 | Sirius |
| 1 | 3\13 | 438.91 | 9/7 | BPS |
| 1 | 4\13 | 585.22 | 7/5 | Canopus |
| 1 | 5\13 | 731.63 | 75/49 | |
| 1 | 6\13 | 877.83 | 5/3 | Arcturus |
Music
See also: Bohlen–Pierce scale/Music
- 13ed3 (2026)
See also
- Bohlen-p_et
- Catalog of 3.5.7 subgroup rank two temperaments
- No-twos subgroup temperaments#3.5.7 subgroup temperaments
- 19ED5: relative ED5
- 23ED7: relative ED7