13edt: Difference between revisions
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{{Infobox ET}} | |||
{{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]]. | |||
{| class="wikitable" | 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 == | |||
{{Main|Intervals of BP}} | |||
{| class="wikitable center-all right-2 right-3" | |||
|- | |||
! Steps | |||
! [[Cent]]s | |||
! [[Hekt]]s | |||
! [[4L 5s (3/1-equivalent)|Enneatonic]]<br />degree | |||
! 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 | |||
| 146.3 | |||
| 100 | |||
| A1/m2 | |||
| [[49/45]] (−1.1{{c}}); [[27/25]] (+13.1{{c}}) | |||
| F | |||
|- | |||
| 2 | |||
| 292.6 | |||
| 200 | |||
| M2/d3 | |||
| [[25/21]] (−9.2{{c}}) | |||
| F#, Gb | |||
|- | |||
| 3 | |||
| 438.9 | |||
| 300 | |||
| A2/P3/d4 | |||
| [[9/7]] (+3.8{{c}}) | |||
| G | |||
|- | |||
| 4 | |||
| 585.2 | |||
| 400 | |||
| A3/m4/d5 | |||
| [[7/5]] (+2.7{{c}}) | |||
| H | |||
|- | |||
| 5 | |||
| 731.5 | |||
| 500 | |||
| M4/m5 | |||
| [[75/49]] (−5.4{{c}}) | |||
| H#, Jb | |||
|- | |||
| 6 | |||
| 877.8 | |||
| 600 | |||
| A4/M5 | |||
| [[5/3]] (−6.5{{c}}) | |||
| J | |||
|- | |- | ||
| 7 | |||
| 1024.1 | |||
| 700 | |||
| A5/m6/d7 | |||
| [[9/5]] (+6.5{{c}}) | |||
| A | |||
|- | |- | ||
| | | 8 | ||
| | | 1170.4 | ||
| | | 800 | ||
| | | M6/m7 | ||
| | | [[49/25]] (+5.4{{c}}) | ||
| A#, Bb | |||
| | |||
|- | |- | ||
| | | 9 | ||
| | | 1316.7 | ||
| | | 900 | ||
| | | A6/M7/d8 | ||
| [[15/7]] (−2.7{{c}}) | |||
| B | |||
|- | |- | ||
| | | 10 | ||
| | | 1463.0 | ||
| | | 1000 | ||
| | | P8/d9 | ||
| [[7/3]] (−3.8{{c}}) | |||
| C | |||
|- | |- | ||
| | | | 11 | ||
| | | | 1609.3 | ||
| | | 1100 | ||
| | | | A8/m9 | ||
| | | | [[63/25]] (+9.2{{c}}) | ||
| | | | C#, Db | ||
|- | |||
| 12 | |||
| 1755.7 | |||
| 1200 | |||
| M9/d10 | |||
| [[135/49]] (+1.1{{c}}); [[25/9]] (−13.1{{c}}) | |||
| D | |||
|- | |||
| 13 | |||
| 1902.0 | |||
| 1300 | |||
| A9/P10 | |||
| [[3/1]] | |||
| E | |||
|} | |||
== JI approximation == | |||
[[File:13ed3-17-001.svg|alt=alt : Your browser has no SVG support.]] | |||
== 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>Equave stretch (¢) | |||
! colspan="2" | Tuning error | |||
|- | |- | ||
| | ! [[TE error|Absolute]] (¢) | ||
! [[TE simple badness|Relative]] (%) | |||
| | |||
|- | |- | ||
| | | | 3.5.7 | ||
| | | | 245/243, 3125/3087 | ||
| | | [{{val| 13 19 23 }}] (b13) | ||
| | | | +1.393 | ||
| | | 1.150 | ||
| 0.79 | |||
| | | |} | ||
=== Rank-2 temperaments === | |||
{| class="wikitable center-all right-3 left-5" | |||
|+ style="font-size: 105%;" | Table of rank-2 temperaments by generator | |||
|- | |- | ||
! Periods<br />per tritave | |||
! Generator<br />(reduced) | |||
! Cents<br />(reduced) | |||
! Associated<br />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 | |||
| | | | ||
|- | |- | ||
| | 13 | | 1 | ||
| | | 6\13 | ||
| 877.83 | |||
| | | 5/3 | ||
| [[Arcturus]] | |||
| | |||
|} | |} | ||
==See also== | == Music == | ||
*[[Catalog of 3.5.7 subgroup rank two temperaments]] | See also: [[Bohlen–Pierce scale/Music]] | ||
; [[Bryan Deister]] | |||
* [https://www.youtube.com/shorts/dKFwJsxE3VU ''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|19ED5]]: relative ED5 | |||
* [[23ed7|23ED7]]: relative ED7 | |||
[[Category: | [[Category:Tritave]] | ||
[[Category: | [[Category:Macrotonal]] | ||
[[Category: | [[Category:Nonoctave]] | ||
[[ | [[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