13edt: Difference between revisions
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{{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]] degree | ||
! Corresponding 3.5.7 subgroup intervals | ! Corresponding | ||
3.5.7 subgroup <br> | |||
intervals | |||
! [[ | ! [[Lambda ups and downs notation|Lambda]] | ||
(sLsLsLsLs, <br> | |||
E = 1/1) | |||
|- | |- | ||
| 0 | | 0 | ||
| Line 35: | Line 37: | ||
| P1 | | P1 | ||
| 1/1 | | 1/1 | ||
| | | E | ||
|- | |- | ||
| 1 | | 1 | ||
| Line 43: | Line 43: | ||
| 100 | | 100 | ||
| A1/m2 | | A1/m2 | ||
| | | [[49/45]] (-1.1c); [[27/25]] (+13.1c) | ||
| F | |||
| | |||
|- | |- | ||
| 2 | | 2 | ||
| Line 52: | Line 50: | ||
| 200 | | 200 | ||
| M2/d3 | | M2/d3 | ||
| [[25/21]] | | [[25/21]] (-9.2c) | ||
| | | F#, Gb | ||
|- | |- | ||
| 3 | | 3 | ||
| Line 61: | Line 57: | ||
| 300 | | 300 | ||
| A2/P3/d4 | | A2/P3/d4 | ||
| [[9/7]] | | [[9/7]] (+3.8c) | ||
| | | G | ||
|- | |- | ||
| 4 | | 4 | ||
| Line 70: | Line 64: | ||
| 400 | | 400 | ||
| A3/m4/d5 | | A3/m4/d5 | ||
| [[7/5]] | | [[7/5]] (+2.7c) | ||
| | | H | ||
|- | |- | ||
| 5 | | 5 | ||
| Line 79: | Line 71: | ||
| 500 | | 500 | ||
| M4/m5 | | M4/m5 | ||
| [[75/49]] | | [[75/49]] (-5.4c) | ||
| | | H#, Jb | ||
|- | |- | ||
| 6 | | 6 | ||
| Line 88: | Line 78: | ||
| 600 | | 600 | ||
| A4/M5 | | A4/M5 | ||
| [[5/3]] | | [[5/3]] (-6.5c) | ||
| | | J | ||
|- | |- | ||
| 7 | | 7 | ||
| Line 97: | Line 85: | ||
| 700 | | 700 | ||
| A5/m6/d7 | | A5/m6/d7 | ||
| [[9/5]] | | [[9/5]] (+6.5c) | ||
| | | A | ||
|- | |- | ||
| 8 | | 8 | ||
| Line 106: | Line 92: | ||
| 800 | | 800 | ||
| M6/m7 | | M6/m7 | ||
| [[49/25]] | | [[49/25]] (+5.4c) | ||
| | | A#, Bb | ||
|- | |- | ||
| 9 | | 9 | ||
| Line 115: | Line 99: | ||
| 900 | | 900 | ||
| A6/M7/d8 | | A6/M7/d8 | ||
| [[15/7]] | | [[15/7]] (-2.7c) | ||
| | | B | ||
|- | |- | ||
| 10 | | 10 | ||
| Line 124: | Line 106: | ||
| 1000 | | 1000 | ||
| P8/d9 | | P8/d9 | ||
| [[7/3]] | | [[7/3]] (-3.8c) | ||
| | | C | ||
|- | |- | ||
| 11 | | 11 | ||
| Line 133: | Line 113: | ||
| 1100 | | 1100 | ||
| A8/m9 | | A8/m9 | ||
| [[63/25]] | | [[63/25]] (+9.2c) | ||
| | | C#, Db | ||
|- | |- | ||
| 12 | | 12 | ||
| Line 142: | Line 120: | ||
| 1200 | | 1200 | ||
| M9/d10 | | M9/d10 | ||
| [[ | | [[135/49]] (+1.1c); [[25/9]] (-13.1c) | ||
| | | D | ||
|- | |- | ||
| 13 | | 13 | ||
| Line 152: | Line 128: | ||
| A9/P10 | | A9/P10 | ||
| [[3/1]] | | [[3/1]] | ||
| | | E | ||
|} | |} | ||
Revision as of 22:05, 5 October 2024
| ← 12edt | 13edt | 14edt → |

13 equal divisions of the tritave (13edt) is the nonoctave tuning system derived by dividing the tritave (3/1) into 13 equal steps of 146.3 cents each, or the thirteenth 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.
It 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 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 no-2 3/1-equave-7-limit, 13edt maintains the smallest relative error of any EDT until 258edt and 271edt, and the smallest absolute error until 56edt.
Theory
| Harmonic | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Error | Absolute (¢) | -29.57 | +0.00 | -59.13 | -6.53 | -29.57 | -3.83 | +57.61 | +0.00 | -36.10 | -54.80 | -59.13 |
| Relative (%) | -20.2 | +0.0 | -40.4 | -4.5 | -20.2 | -2.6 | +39.4 | +0.0 | -24.7 | -37.5 | -40.4 | |
| Steps (reduced) |
8 (8) |
13 (0) |
16 (3) |
19 (6) |
21 (8) |
23 (10) |
25 (12) |
26 (0) |
27 (1) |
28 (2) |
29 (3) | |
| Harmonic | 3 | 5 | 7 | 9 | 11 | 13 | 15 | 17 | 19 | 21 | 23 | 25 | 27 | 29 | 31 | 33 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Error | Absolute (¢) | +0.00 | -6.53 | -3.83 | +0.00 | -54.80 | -51.40 | -6.53 | +69.39 | +23.14 | -3.83 | -15.02 | -13.07 | +0.00 | +22.59 | +53.44 | -54.80 |
| Relative (%) | +0.0 | -4.5 | -2.6 | +0.0 | -37.5 | -35.1 | -4.5 | +47.4 | +15.8 | -2.6 | -10.3 | -8.9 | +0.0 | +15.4 | +36.5 | -37.5 | |
| Steps (reduced) |
13 (0) |
19 (6) |
23 (10) |
26 (0) |
28 (2) |
30 (4) |
32 (6) |
34 (8) |
35 (9) |
36 (10) |
37 (11) |
38 (12) |
39 (0) |
40 (1) |
41 (2) |
41 (2) | |
Intervals
| Steps | Cents | Hekts | Enneatonic degree | Corresponding
3.5.7 subgroup |
Lambda
(sLsLsLsLs, |
|---|---|---|---|---|---|
| 0 | 0 | 0 | P1 | 1/1 | E |
| 1 | 146.3 | 100 | A1/m2 | 49/45 (-1.1c); 27/25 (+13.1c) | F |
| 2 | 292.6 | 200 | M2/d3 | 25/21 (-9.2c) | F#, Gb |
| 3 | 438.9 | 300 | A2/P3/d4 | 9/7 (+3.8c) | G |
| 4 | 585.2 | 400 | A3/m4/d5 | 7/5 (+2.7c) | H |
| 5 | 731.5 | 500 | M4/m5 | 75/49 (-5.4c) | H#, Jb |
| 6 | 877.8 | 600 | A4/M5 | 5/3 (-6.5c) | J |
| 7 | 1024.1 | 700 | A5/m6/d7 | 9/5 (+6.5c) | A |
| 8 | 1170.4 | 800 | M6/m7 | 49/25 (+5.4c) | A#, Bb |
| 9 | 1316.7 | 900 | A6/M7/d8 | 15/7 (-2.7c) | B |
| 10 | 1463.0 | 1000 | P8/d9 | 7/3 (-3.8c) | C |
| 11 | 1609.3 | 1100 | A8/m9 | 63/25 (+9.2c) | C#, Db |
| 12 | 1755.7 | 1200 | M9/d10 | 135/49 (+1.1c); 25/9 (-13.1c) | 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 |
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