23edo

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← 22edo 23edo 24edo →
Prime factorization 23 (prime)
Step size 52.1739 ¢ 
Fifth 13\23 (678.261 ¢)
Semitones (A1:m2) -1:4 (-52.17 ¢ : 208.7 ¢)
Dual sharp fifth 14\23 (730.435 ¢)
Dual flat fifth 13\23 (678.261 ¢)
Dual major 2nd 4\23 (208.696 ¢)
(semiconvergent)
Consistency limit 5
Distinct consistency limit 5
English Wikipedia has an article on:

23 equal divisions of the octave (abbreviated 23edo or 23ed2), also called 23-tone equal temperament (23tet) or 23 equal temperament (23et) when viewed under a regular temperament perspective, is the tuning system that divides the octave into 23 equal parts of about 52.2 ¢ each. Each step represents a frequency ratio of 21/23, or the 23rd root of 2.

Theory

23edo is significant in that it is the last edo that has no diatonic perfect fifths and not even 5edo or 7edo fifths. It is also the last edo that fails to approximate the 3rd, 5th, 7th, and 11th harmonics within 20 cents, which makes it well-suited for musicians seeking to explore harmonic territory that is unusual even for the average microtonalist. Oddly, despite the fact that it fails to approximate these harmonics, it approximates the intervals between them (5/3, 7/3, 11/3, 7/5, 11/5, 11/7) and combinations of them (15/8, 21/16, 33/32, 35/32, 55/32, 77/64) very well. The lowest harmonics well-approximated by 23edo are 9, 13, 15, 17, 21, 23, 31, 33 and 35.

Mapping

As with 9edo, 16edo, and 25edo, one way to treat 23edo is as a tuning of the mavila temperament, tempering out the "comma" of 135/128 and equating three acute 4/3's with 5/1 (related to the Armodue system). This means mapping "3/2" to 13 degrees of 23, and results in a 7-note antidiatonic scale of 3–3–4–3–3–3–4 (in steps of 23edo), which extends to a 9-note superdiatonic scale (3–3–3–1–3–3–3–3–1). One can notate 23edo using the Armodue system, but just like notating 17edo with familiar diatonic notation, flats will be lower in pitch than enharmonic sharps, because in 23edo, the "Armodue 6th" is sharper than it is in 16edo, just like the diatonic 5th in 17edo is sharper than in 12edo. In other words, 2b is lower in pitch than 1#, just like how in 17edo Eb is lower than D#.

However, one can also map 3/2 to 14 degrees of 23edo without significantly increasing the error, taking us to a 7-limit temperament where two broad 3/2's equals 7/3, meaning 28/27 is tempered out, and six 4/3's octave-reduced equals 5/4, meaning 4096/3645 is tempered out. Both of these are very large commas, so this is not at all an accurate temperament, but it is related to 13edo and 18edo and produces mos scales of 5 and 8 notes: 5–5–4–5–4 (antipentic) and 4–1–4–1–4–4–1–4 (the "quartertone" version of the Blackwood/Rapoport/Wilson 13edo "subminor" scale). Alternatively we can treat this temperament as a 2.9.21 subgroup, and instead of calling 9 degrees of 23edo a sub-"4/3", we can call it 21/16. Here three 21/16's gets us to 9/4, meaning 1029/1024 is tempered out. This allows us to treat a triad of 0–4–9 degrees of 23edo as an approximation to 16:18:21, and 0–5–9 as 1/(16:18:21); both of these triads are abundant in the 8-note mos scale.

23edo has good approximations for 5/3, 11/7, 13 and 17, among many others, allowing it to represent the 2.5/3.11/7.13.17 just intonation subgroup. If to this subgroup is added the commas of no-19's 23-limit 46edo, the larger no-19's 23-limit 2*23 subgroup 2.9.15.21.33.13.17.23 is obtained. This is the largest subgroup on which 23 has the same tuning and commas as does no-19's 23-limit 46edo, and may be regarded as a basis for analyzing the harmony of 23edo so far, as approximations to just intervals goes. If one dares to take advantage of this harmony by using 23edo as a period, you get icositritonic, a 23rd-octave temperament, so that the harmony of 23edo is adequately explained by what harmonies you can achieve using only periods and zero generators.

See Harmony of 23edo for more details.

Odd harmonics

Approximation of odd harmonics in 23edo
Harmonic 3 5 7 9 11 13 15 17 19 21 23
Error Absolute (¢) -23.7 -21.1 +22.5 +4.8 +22.6 -5.7 +7.4 -0.6 +15.5 -1.2 -2.2
Relative (%) -45.4 -40.4 +43.1 +9.2 +43.3 -11.0 +14.2 -1.2 +29.8 -2.3 -4.2
Steps
(reduced)
36
(13)
53
(7)
65
(19)
73
(4)
80
(11)
85
(16)
90
(21)
94
(2)
98
(6)
101
(9)
104
(12)

Subsets and supersets

23edo is the 9th prime edo, following 19edo and coming before 29edo, so it does not contain any nontrivial subset edos, though it contains 23ed4. 46edo, which doubles it, considerably improves most of its approximations of lower harmonics.

Miscellany

23edo was proposed by ethnomusicologist Erich von Hornbostel as the result of continuing a circle of "blown" fifths of ~678-cent fifths that (he argued) resulted from "overblowing" a bamboo pipe.

Selected just intervals

The following tables show how 15-odd-limit intervals are represented in 23edo. Prime harmonics are in bold; inconsistent intervals are in italics.

15-odd-limit intervals in 23edo (direct approximation, even if inconsistent)
Interval and complement Error (abs, ¢) Error (rel, %)
1/1, 2/1 0.000 0.0
11/7, 14/11 0.117 0.2
5/3, 6/5 2.598 5.0
9/8, 16/9 4.786 9.2
13/8, 16/13 5.745 11.0
11/6, 12/11 5.885 11.3
7/6, 12/7 6.001 11.5
15/8, 16/15 7.383 14.2
11/10, 20/11 8.482 16.3
7/5, 10/7 8.599 16.5
13/9, 18/13 10.531 20.2
15/13, 26/15 13.129 25.2
15/14, 28/15 15.095 28.9
15/11, 22/15 15.212 29.2
13/10, 20/13 15.351 29.4
9/7, 14/9 17.693 33.9
11/9, 18/11 17.809 34.1
13/12, 24/13 17.949 34.4
5/4, 8/5 21.096 40.4
7/4, 8/7 22.478 43.1
11/8, 16/11 22.595 43.3
3/2, 4/3 23.694 45.4
13/11, 22/13 23.834 45.7
13/7, 14/13 23.950 45.9
9/5, 10/9 25.882 49.6
15-odd-limit intervals in 23edo (patent val mapping)
Interval and complement Error (abs, ¢) Error (rel, %)
1/1, 2/1 0.000 0.0
11/7, 14/11 0.117 0.2
5/3, 6/5 2.598 5.0
13/8, 16/13 5.745 11.0
13/10, 20/13 15.351 29.4
13/12, 24/13 17.949 34.4
5/4, 8/5 21.096 40.4
7/4, 8/7 22.478 43.1
11/8, 16/11 22.595 43.3
3/2, 4/3 23.694 45.4
9/5, 10/9 26.292 50.4
13/7, 14/13 28.223 54.1
13/11, 22/13 28.340 54.3
15/13, 26/15 39.045 74.8
13/9, 18/13 41.643 79.8
7/5, 10/7 43.575 83.5
11/10, 20/11 43.691 83.7
15/8, 16/15 44.790 85.8
7/6, 12/7 46.173 88.5
11/6, 12/11 46.289 88.7
9/8, 16/9 47.388 90.8
15/14, 28/15 67.269 128.9
15/11, 22/15 67.386 129.2
9/7, 14/9 69.867 133.9
11/9, 18/11 69.983 134.1

Notation

Conventional notation

23edo can be notated with conventional notation, including the staff, note names, relative notation, etc. in two ways.

The first, melodic notation, defines sharp/flat, major/minor, and aug/dim in terms of the antidiatonic scale, such that sharp is higher pitched than flat, and major/aug is wider than minor/dim, as would be expected. Because it does not follow diatonic conventions, conventional interval arithmetic no longer works, e.g. M2 + M2 is not M3, and D + M2 is not E. Because antidiatonic is the sister scale to diatonic, you can solve this by swapping major and minor in interval arithmetic rules. Note that the notes that form chords are different from in diatonic: for example, a major chord, P1–M3–P5, is approximately 4:5:6 as would be expected, but is notated C–E♯–G on C.

Alternatively, one can essentially pretend the antidiatonic scale is a normal diatonic, meaning that sharp is lower in pitch than flat (since the "S" step is larger than the "L" step) and major/aug is narrower than minor/dim, known as harmonic notation. The primary purpose of doing this is to allow music notated in 12edo or another diatonic system to be directly translated on the fly, or to allow support for 23edo in tools that only allow chain-of-fifths notation, and it carries over the way interval arithmetic works from diatonic notation, at the cost of notating the sizes of intervals and the shapes of chords incorrectly: that is, a major chord, P1–M3–P5, is notated C–E–G on C, but is no longer ~4:5:6 (since the third is closer to a minor third).

For the sake of clarity, the first notation is commonly called melodic notation, and the second is called harmonic notation, but this is a bit of a misnomer as both preserve different features of the notation of harmony.

Comparison of notations
Notation P1–M3–P5 ~ 4:5:6 P1–M3–P5 = C–E–G on C
Diatonic No Yes
Antidiatonic Yes No

Sagittal notation

Best fifth notation

This notation uses the same sagittal sequence as EDOs 28 and 33.

Sagittal notationPeriodic table of EDOs with sagittal notationlimma-fraction notation

Second-best fifth notation

This notation uses the same sagittal sequence as EDOs 30, 37, and 44.

Sagittal notationPeriodic table of EDOs with sagittal notationapotome-fraction notation

Armodue notation

Armodue notation is a nonatonic notation that uses the numbers 1-9 as note names.

Degree Cents Approximate
Ratios [1]
Major wider
than minor
Major narrower
than minor
Armodue
Notation
Notes
0 0.000 1/1 P1 D P1 D 1
1 52.174 33/32, 34/33 A1 D# d1 Db 2b
2 104.348 17/16, 16/15, 18/17 d2 Eb A2 E# 1# Less than 1 cent off 17/16
3 156.522 11/10, 12/11, 35/32 m2 E M2 E 2
4 208.696 9/8, 44/39 M2 E# m2 Eb 3b
5 260.870 7/6, 15/13, 29/25 A2, d3 Ex, Fbb d2, A3 Ebb, Fx 2#
6 313.043 6/5 m3 Fb M3 F# 3 Much better 6/5 than 12-edo
7 365.217 16/13, 21/17, 26/21 M3 F m3 F 4b
8 417.391 14/11, 33/26 A3 F# d3 Fb 3# Practically just 14/11
9 469.565 21/16, 17/13 d4 Gb A4 G# 4
10 521.739 23/17, 88/65, 256/189 P4 G P4 G 5
11 573.913 7/5, 32/23, 46/33 A4 G# d4 Gb 6b
12 626.087 10/7, 23/16, 33/23 d5 Ab A5 A# 5#
13 678.261 34/23, 65/44, 189/128 P5 A P5 A 6 Great Hornbostel generator
14 730.435 32/21, 26/17 A5 A# d5 Ab 7b
15 782.609 11/7, 52/33 d6 Bb A6 B# 6# Practically just 11/7
16 834.783 13/8, 34/21, 21/13 m6 B M6 B 7
17 886.957 5/3 M6 B# m6 Bb 8b Much better 5/3 than 12-edo
18 939.130 12/7, 26/15, 50/29 A6, d7 Bx, Cbb d6, A7 Bbb, Cx 7#
19 991.304 16/9, 39/22 m7 Cb M7 C# 8
20 1043.478 11/6, 20/11, 64/35 M7 C m7 C 9b
21 1095.652 15/8, 17/9, 32/17 A7 C# d7 Cb 8# Less than 1 cent off 32/17
22 1147.826 33/17, 64/33 d8 Db A8 D# 9
23 1200.000 2/1 P8 D P8 D 1
  1. Based on treating 23-EDO as a 2.9.15.21.33.13.17 subgroup temperament; other approaches are possible.


Ciclo Icositrifonía.png

Approximation to irrational intervals

23edo has good approximations of acoustic phi on 16\23, and pi on 38\23. Not until 72 do we find a better edo in terms of absolute error, and not until 749 do we find one in terms of relative error.

Direct approximation
Interval Error (abs, ¢)
π 0.813
π/ϕ 0.879
ϕ 1.692

Regular temperament properties

Uniform maps

13-limit uniform maps between 22.8 and 23.2
Min. size Max. size Wart notation Map
22.6916 22.8351 23deff 23 36 53 64 79 84]
22.8351 22.9754 23de 23 36 53 64 79 85]
22.9754 22.9807 23e 23 36 53 65 79 85]
22.9807 23.0289 23 23 36 53 65 80 85]
23.0289 23.0412 23b 23 37 53 65 80 85]
23.0412 23.1054 23bc 23 37 54 65 80 85]
23.1054 23.2697 23bcf 23 37 54 65 80 86]

Commas

23et tempers out the following commas. This assumes the val 23 36 53 65 80 85]. Also note the discussion above, where there are some commas mentioned that are not in the standard comma list (e.g., 28/27).

Prime
limit
Ratio Monzo Cents Color name Name(s)
5 135/128 [-7 3 1 92.18 Layobi Mavila comma, major chroma
5 15625/15552 [-6 -5 6 8.11 Tribiyo Kleisma, semicomma majeur
7 36/35 [2 2 -1 -1 48.77 Rugu Mint comma, septimal quartertone
7 525/512 [-9 1 2 1 43.41 Lazoyoyo Avicennma, Avicenna's enharmonic diesis
7 4000/3969 [5 -4 3 -2 13.47 Rurutriyo Octagar comma
7 6144/6125 [11 1 -3 -2 5.36 Sarurutrigu Porwell comma
11 100/99 [2 -2 2 0 -1 17.40 Luyoyo Ptolemisma
11 441/440 [-3 2 -1 2 -1 3.93 Luzozogu Werckisma

Octave stretch or compression

23edo is not often taken seriously as a tuning except by those interested in extreme xenharmony. Its fifths are significantly flat, and is neighbors 22edo and 24edo generally get more attention.

However, when using a slightly stretched octave of around 1206 cents, 23edo looks much better, and it approximates the perfect fifth (and various other intervals involving the 5th, 7th, 11th, and 13th harmonics) to within 18 cents or so. If we can tolerate errors around this size in 12edo, we can probably tolerate them in stretched-23 as well.

Stretched-23edo is one of the best tunings to use for exploring the antidiatonic scale since its fifth is more consonant and less "wolfish" than fifths in other pelogic family temperaments.

What follows is a comparison of compressed- and stretched-octave 23edo tunings.

86zpi
  • Step size: 51.653 ¢, octave size: 1188.0 ¢
  • Approximates all harmonics <9 within 24.0 ¢

Compressing the octave of 23edo by around 12 ¢ results in improved primes 5, 11 and 13, but worse primes 2, 3 and 7. The tuning 86zpi does this.

Approximation of harmonics in 86zpi
Harmonic 2 3 4 5 6 7 8 9 10 11 12
Error Absolute (¢) -12.0 +9.2 -24.0 +2.9 -2.8 -11.4 +15.7 +18.4 -9.0 -19.1 -14.8
Relative (%) -23.2 +17.8 -46.4 +5.7 -5.4 -22.0 +30.4 +35.6 -17.5 -36.9 -28.6
Step 23 37 46 54 60 65 70 74 77 80 83
Approximation of harmonics in 86zpi (continued)
Harmonic 13 14 15 16 17 18 19 20 21 22 23 24
Error Absolute (¢) +1.6 -23.4 +12.2 +3.7 +2.1 +6.4 +16.1 -21.0 -2.2 +20.6 -4.7 +24.9
Relative (%) +3.2 -45.2 +23.5 +7.2 +4.0 +12.5 +31.2 -40.7 -4.2 +39.9 -9.1 +48.2
Step 86 88 91 93 95 97 99 100 102 104 105 107
60ed6
  • Step size: 51.700 ¢, octave size: 1189.1 ¢
  • Approximates all harmonics <9 within 21.8 ¢

Compressing the octave of 23edo by around 11 ¢ results in improved primes 3, 5, 7 and 11, but a worse prime 2. The tuning 60ed6 does this. So does the tuning 105ed23 whose octave is identical within 0.01 ¢.

Approximation of harmonics in 60ed6
Harmonic 2 3 4 5 6 7 8 9 10 11 12
Error Absolute (¢) -10.9 +10.9 -21.8 +5.4 +0.0 -8.4 +18.9 +21.8 -5.5 -15.4 -10.9
Relative (%) -21.1 +21.1 -42.2 +10.5 +0.0 -16.2 +36.6 +42.2 -10.6 -29.7 -21.1
Steps
(reduced)
23
(23)
37
(37)
46
(46)
54
(54)
60
(0)
65
(5)
70
(10)
74
(14)
77
(17)
80
(20)
83
(23)
Approximation of harmonics in 60ed6 (continued)
Harmonic 13 14 15 16 17 18 19 20 21 22 23 24
Error Absolute (¢) +5.6 -19.3 +16.4 +8.0 +6.5 +10.9 +20.7 -16.4 +2.5 +25.4 +0.1 -21.8
Relative (%) +10.8 -37.3 +31.7 +15.5 +12.5 +21.1 +40.1 -31.7 +4.9 +49.1 +0.3 -42.2
Steps
(reduced)
86
(26)
88
(28)
91
(31)
93
(33)
95
(35)
97
(37)
99
(39)
100
(40)
102
(42)
104
(44)
105
(45)
106
(46)
85zpi
  • Step size: 52.114 ¢, octave size: 1198.6 ¢
  • Approximates all harmonics <9 within 24.9 ¢

Compressing the octave of 23edo by around 1.5 ¢ results in improved primes 7 and 11, but worse primes 2, 3, 5 and 13. The tuning 85zpi does this. So does the tuning 73ed9 whose octave is identical within 0.02 ¢.

Approximation of harmonics in 85zpi
Harmonic 2 3 4 5 6 7 8 9 10 11 12
Error Absolute (¢) -1.4 -25.9 -2.8 -24.3 +24.9 +18.6 -4.1 +0.4 -25.6 +17.8 +23.5
Relative (%) -2.6 -49.6 -5.3 -46.6 +47.8 +35.7 -7.9 +0.8 -49.2 +34.2 +45.1
Step 23 36 46 53 60 65 69 73 76 80 83
Approximation of harmonics in 85zpi (continued)
Harmonic 13 14 15 16 17 18 19 20 21 22 23 24
Error Absolute (¢) -10.8 +17.2 +2.0 -5.5 -6.2 -1.0 +9.7 +25.1 -7.3 +16.4 -8.4 +22.1
Relative (%) -20.8 +33.0 +3.8 -10.6 -12.0 -1.9 +18.5 +48.1 -13.9 +31.5 -16.2 +42.5
Step 85 88 90 92 94 96 98 100 101 103 104 106
23edo
  • Step size: 52.174 ¢, octave size: 1200.0 ¢
  • Approximates all harmonics <9 within 23.7 ¢

Pure-octaves 23edo.

Approximation of harmonics in 23edo
Harmonic 2 3 4 5 6 7 8 9 10 11 12
Error Absolute (¢) +0.0 -23.7 +0.0 -21.1 -23.7 +22.5 +0.0 +4.8 -21.1 +22.6 -23.7
Relative (%) +0.0 -45.4 +0.0 -40.4 -45.4 +43.1 +0.0 +9.2 -40.4 +43.3 -45.4
Steps
(reduced)
23
(0)
36
(13)
46
(0)
53
(7)
59
(13)
65
(19)
69
(0)
73
(4)
76
(7)
80
(11)
82
(13)
Approximation of harmonics in 23edo (continued)
Harmonic 13 14 15 16 17 18 19 20 21 22 23 24
Error Absolute (¢) -5.7 +22.5 +7.4 +0.0 -0.6 +4.8 +15.5 -21.1 -1.2 +22.6 -2.2 -23.7
Relative (%) -11.0 +43.1 +14.2 +0.0 -1.2 +9.2 +29.8 -40.4 -2.3 +43.3 -4.2 -45.4
Steps
(reduced)
85
(16)
88
(19)
90
(21)
92
(0)
94
(2)
96
(4)
98
(6)
99
(7)
101
(9)
103
(11)
104
(12)
105
(13)
23et, 13-limit WE tuning
  • Step size: 52.237 ¢, octave size: 1201.5 ¢
  • Approximates all harmonics <9 within 25.7 ¢

Stretching the octave of 23edo by around 1.5 ¢ results in improved primes 3, 5 and 13, but worse primes 2, 7 and 11. Its 13-limit WE tuning and 13-limit TE tuning both do this. So does the tuning 85ed13 whose octave is identical within 0.1 ¢.

Approximation of harmonics in 23et, 13-limit WE tuning
Harmonic 2 3 4 5 6 7 8 9 10 11 12
Error Absolute (¢) +1.5 -21.4 +2.9 -17.8 -20.0 -25.7 +4.4 +9.4 -16.3 -24.6 -18.5
Relative (%) +2.8 -41.0 +5.6 -34.0 -38.2 -49.1 +8.3 +18.0 -31.2 -47.1 -35.5
Step 23 36 46 53 59 64 69 73 76 79 82
Approximation of harmonics in 23et, 13-limit WE tuning (continued)
Harmonic 13 14 15 16 17 18 19 20 21 22 23 24
Error Absolute (¢) -0.4 -24.2 +13.1 +5.8 +5.3 +10.8 +21.7 -14.9 +5.2 -23.1 +4.4 -17.1
Relative (%) -0.7 -46.3 +25.0 +11.1 +10.2 +20.8 +41.6 -28.4 +9.9 -44.3 +8.4 -32.7
Step 85 87 90 92 94 96 98 99 101 102 104 105
23et, 2.3.5.13 WE tuning
  • Step size: 52.447 ¢, octave size: 1206.3 ¢
  • Approximates all harmonics <9 within 18.8 ¢

Stretching the octave of 23edo by around 6 ¢ results in improved primes 3, 5, 7 and 11, but worse primes 2 and 13. Its 2.3.5.13 WE tuning and 2.3.5.13 TE tuning both do this. So does the tuning 76ed10 whose octave is identical within 0.01 ¢.

Approximation of harmonics in 23et, 2.3.5.13 WE tuning
Harmonic 2 3 4 5 6 7 8 9 10 11 12
Error Absolute (¢) +6.3 -13.9 +12.6 -6.6 -7.6 -12.2 +18.8 +24.7 -0.3 -8.0 -1.3
Relative (%) +12.0 -26.4 +24.0 -12.6 -14.5 -23.3 +35.9 +47.1 -0.7 -15.3 -2.5
Step 23 36 46 53 59 64 69 73 76 79 82
Approximation of harmonics in 23et, 2.3.5.13 WE tuning (continued)
Harmonic 13 14 15 16 17 18 19 20 21 22 23 24
Error Absolute (¢) +17.5 -5.9 -20.5 +25.1 +25.1 -21.4 -10.2 +5.9 -26.1 -1.7 +26.2 +5.0
Relative (%) +33.3 -11.3 -39.1 +47.9 +47.8 -40.9 -19.4 +11.3 -49.7 -3.3 +50.0 +9.5
Step 85 87 89 92 94 95 97 99 100 102 104 105
59ed6
  • Step size: 52.575 ¢, octave size: 1209.2 ¢
  • Approximates all harmonics <9 within 24.9 ¢

Stretching the octave of 23edo by around 9 ¢ results in improved primes 3, 5, 7 and 11, but worse primes 2 and 13. The tuning 59ed6 does this. So does the tuning 53ed5 whose octave is identical within 0.01 ¢.

Approximation of harmonics in 59ed6
Harmonic 2 3 4 5 6 7 8 9 10 11 12
Error Absolute (¢) +9.2 -9.2 +18.5 +0.2 +0.0 -4.0 -24.9 -18.5 +9.4 +2.1 +9.2
Relative (%) +17.6 -17.6 +35.1 +0.4 +0.0 -7.6 -47.3 -35.1 +17.9 +4.1 +17.6
Steps
(reduced)
23
(23)
36
(36)
46
(46)
53
(53)
59
(0)
64
(5)
68
(9)
72
(13)
76
(17)
79
(20)
82
(23)
Approximation of harmonics in 59ed6 (continued)
Harmonic 13 14 15 16 17 18 19 20 21 22 23 24
Error Absolute (¢) -24.2 +5.2 -9.0 -15.6 -15.4 -9.2 +2.3 +18.7 -13.2 +11.4 -13.0 +18.5
Relative (%) -46.0 +10.0 -17.2 -29.7 -29.4 -17.6 +4.4 +35.5 -25.2 +21.7 -24.7 +35.1
Steps
(reduced)
84
(25)
87
(28)
89
(30)
91
(32)
93
(34)
95
(36)
97
(38)
99
(40)
100
(41)
102
(43)
103
(44)
105
(46)
84zpi
  • Step size: 52.615 ¢, octave size: 1210.1 ¢
  • Approximates all harmonics <9 within 22.2 ¢

Stretching the octave of 23edo by around 10 ¢ results in improved primes 3, 5, 7 and 11, but worse primes 2 and 13. The tuning 84zpi does this.

Approximation of harmonics in 84zpi
Harmonic 2 3 4 5 6 7 8 9 10 11 12
Error Absolute (¢) +10.1 -7.8 +20.3 +2.3 +2.3 -1.5 -22.2 -15.6 +12.4 +5.3 +12.5
Relative (%) +19.3 -14.9 +38.6 +4.3 +4.4 -2.8 -42.2 -29.7 +23.6 +10.0 +23.7
Step 23 36 46 53 59 64 68 72 76 79 82
Approximation of harmonics in 84zpi (continued)
Harmonic 13 14 15 16 17 18 19 20 21 22 23 24
Error Absolute (¢) -20.9 +8.7 -5.5 -12.0 -11.8 -5.5 +6.1 +22.6 -9.3 +15.4 -8.9 +22.6
Relative (%) -39.7 +16.5 -10.5 -22.9 -22.4 -10.4 +11.7 +42.9 -17.6 +29.3 -17.0 +43.0
Step 84 87 89 91 93 95 97 99 100 102 103 105
36edt
  • Step size: 52.832 ¢, octave size: 1215.1 ¢
  • Approximates all harmonics <9 within 22.6 ¢

Stretching the octave of 23edo by around 15 ¢ results in improved primes 3, 5, 7 and 13, but a worse prime 2. The tuning 36edt does this.

Approximation of harmonics in 36edt
Harmonic 2 3 4 5 6 7 8 9 10 11 12
Error Absolute (¢) +15.1 +0.0 -22.6 +13.8 +15.1 +12.4 -7.4 +0.0 -23.9 +22.4 -22.6
Relative (%) +28.7 +0.0 -42.7 +26.1 +28.7 +23.5 -14.0 +0.0 -45.3 +42.4 -42.7
Steps
(reduced)
23
(23)
36
(0)
45
(9)
53
(17)
59
(23)
64
(28)
68
(32)
72
(0)
75
(3)
79
(7)
81
(9)
Approximation of harmonics in 36edt (continued)
Harmonic 13 14 15 16 17 18 19 20 21 22 23 24
Error Absolute (¢) -2.6 -25.3 +13.8 +7.7 +8.4 +15.1 -25.6 -8.8 +12.4 -15.3 +13.4 -7.4
Relative (%) -5.0 -47.8 +26.1 +14.6 +16.0 +28.7 -48.5 -16.6 +23.5 -28.9 +25.4 -14.0
Steps
(reduced)
84
(12)
86
(14)
89
(17)
91
(19)
93
(21)
95
(23)
96
(24)
98
(26)
100
(28)
101
(29)
103
(31)
104
(32)
84ed13
  • Step size: 52.863 ¢, octave size: 1215.9 ¢
  • Approximates all harmonics <9 within 21.1 ¢

Stretching the octave of 23edo by around 16 ¢ results in improved primes 3, 5, 7 and 13, but worse primes 2 and 11. The tuning 84ed13 does this.

Approximation of harmonics in 84ed13
Harmonic 2 3 4 5 6 7 8 9 10 11 12
Error Absolute (¢) +15.9 +1.1 -21.1 +15.4 +17.0 +14.4 -5.3 +2.3 -21.6 +24.9 -20.0
Relative (%) +30.0 +2.1 -40.0 +29.2 +32.1 +27.3 -10.0 +4.3 -40.8 +47.1 -37.9
Steps
(reduced)
23
(23)
36
(36)
45
(45)
53
(53)
59
(59)
64
(64)
68
(68)
72
(72)
75
(75)
79
(79)
81
(81)
Approximation of harmonics in 84ed13 (continued)
Harmonic 13 14 15 16 17 18 19 20 21 22 23 24
Error Absolute (¢) +0.0 -22.6 +16.6 +10.6 +11.3 +18.1 -22.6 -5.7 +15.6 -12.1 +16.7 -4.2
Relative (%) +0.0 -42.7 +31.4 +20.0 +21.5 +34.3 -42.8 -10.8 +29.4 -22.9 +31.5 -7.9
Steps
(reduced)
84
(0)
86
(2)
89
(5)
91
(7)
93
(9)
95
(11)
96
(12)
98
(14)
100
(16)
101
(17)
103
(19)
104
(20)

Scales

Important mosses include:

  • Mavila 2L5s 4334333 (13\23, 1\1)
  • Mavila 7L2s 133313333 (13\23, 1\1)
  • Sephiroth 3L4s 2525252 (7\23, 1\1)
  • Semiquartal 5L4s 332323232 (5\23, 1\1)

The chart below shows some of the mos modes of mavila available in 23edo, mainly Pentatonic (5-note), antidiatonic (7-note), 9- and 16-note mosses. Here the outer ring represents individual step of 23edo itself, while the rings moving inward represent 16, 9, 7 and 5 note mosses:

23edoMavilaMOS.jpg

23-tone mos scales

MOS scale Name
10 10 3
9 9 5
8 8 7
7 7 7 2
6 6 6 5
5 4 5 5 4 3L 2s (oneiro-pentatonic)
5 4 5 4 5
7 1 7 7 1
7 1 7 1 7
5 5 5 5 3 4L 1s (bug pentatonic)
4 4 4 4 4 3 5L 1s (machinoid)
5 1 5 1 5 1 5 4L 3s (smitonic)
3 3 3 5 3 3 3 1L 6s (antiarcheotonic)
4 3 3 3 3 3 4
3 3 4 3 3 3 4 2L 5s (mavila, anti-diatonic)
4 3 3 3 3 4 3
2 5 2 5 2 5 2 3L 4s (mosh)
4 1 4 4 1 4 4 1 5L 3s (oneirotonic)
3 3 3 3 3 3 3 2 7L 1s (porcupoid)
3 3 3 1 3 3 3 3 1 7L 2s (mavila superdiatonic)
3 2 3 2 3 2 3 2 3 5L 4s (bug semiquartal)
3 2 2 3 2 2 3 2 2 2 3L 7s (sephiroid)
4 1 1 4 1 1 4 1 1 4 1 4L 7s (kleistonic)
3 1 3 1 3 1 3 1 3 1 3 Palestine 11
3 1 1 3 1 3 1 1 3 1 3 1 1 5L 8s (ateamtonic)
2 2 2 2 1 2 2 2 1 2 2 2 1 10L 3s (luachoid)
2 2 1 2 2 1 2 2 1 2 2 1 2 1 9L 5s (Brittle Titanium)
2 1 2 2 1 2 2 1 2 2 1 2 2 1 Palestine 14
1 1 1 4 1 1 1 1 4 1 1 1 1 4 3L 11s
3 1 1 1 3 1 1 1 3 1 1 1 3 1 1 4L 11s (mynoid)
2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 8L 7s
2 1 2 1 2 1 1 2 1 2 1 2 1 2 1 1 7L 9s (mavila chromatic)
2 1 1 2 1 1 2 1 1 2 1 1 2 1 1 2 1 Palestine 17
2 1 1 1 2 1 1 2 1 1 1 2 1 1 2 1 1 1 5L 13s
2 1 1 1 1 2 1 1 1 1 2 1 1 1 1 2 1 1 1 4L 15s

While 35edo is the largest edo without a nondegenerate 5L 2s scale, it has both degenerate cases (the equalised 7edo and the collapsed 5edo).

23edo is the largest edo without any form of 5L 2s, including the degenerate cases.

Kosmorsky's Sephiroth modes

Kosmorsky has argued that the most significant modes of 23 edo are those of the 2 2 2 3 2 2 3 2 2 3 scale (3L 7s fair mosh); This is derived from extending the ~1/3 comma tempered 13th Harmonic, two of which add up to the 21st harmonic and three add up to the 17th harmonic almost perfectly. Interestingly, the chord 8:13:21:34 is a fragment of the fibonacci sequence.

Notated in ascending (standard) form. I have named these 10 modes according to the Sephiroth as follows:

2 2 2 3 2 2 3 2 2 3 - Mode Keter

2 2 3 2 2 3 2 2 3 2 - Chesed

2 3 2 2 3 2 2 3 2 2 - Netzach

3 2 2 3 2 2 3 2 2 2 - Malkuth

2 2 3 2 2 3 2 2 2 3 - Binah

2 3 2 2 3 2 2 2 3 2 - Tiferet

3 2 2 3 2 2 2 3 2 2 - Yesod

2 2 3 2 2 2 3 2 2 3 - Chokmah

2 3 2 2 2 3 2 2 3 2 - Gevurah

3 2 2 2 3 2 2 3 2 2 - Hod

Miscellaneous

5 5 1 2 5 5 - Antipental blues (approximated from Dwarf17marv)

7 2 4 6 4 - Arcade (approximated from 32afdo)

6 4 1 2 2 6 2 - Blackened skies (approximated from Compton in 72edo)

5 5 3 7 3 - Geode (approximated from 6afdo)

5 4 2 2 4 2 4 - Lost phantom (approximated from Mavila in 30edo)

6 4 2 1 5 1 4 - Lost spirit (approximated from Meantone in 31edo)

5 2 6 6 4 - Mechanical (approximated from 31afdo)

5 4 4 2 8 - Mushroom (approximated from 30afdo)

6 4 3 7 3 - Nightdrive (approximated from Mavila in 30edo)

6 4 1 2 6 4 - Pelagic (approximated from Mavila in 30edo)

2 3 8 2 8 - Approximation of Pelog lima

4 3 6 6 4 - Springwater (approximated from 8afdo)

2 5 2 4 6 4 - Starship (approximated from 68ifdo)

2 4 6 1 10 - Tightrope (this is the original/default tuning)

6 7 4 2 4 - Underpass (approximated from 10afdo)

2 5 6 6 4 - Volcanic (approximated from 16afdo)

Instruments

Icositriphonic_Guitar.PNG

23-EDD 8-string Guitar by Ron Sword.

Bajo 23-EDD.jpg

23-EDD Bass by Osmiorisbendi.

Baritarra 23-EDD.jpg

23-EDD Baritar by Osmiorisbendi.

Icositritar 1.png

23-EDD 5-string Acoustic Guitar by Tútim Dennsuul Wafiil (RIP).

Teclado Icositrifónico.PNG

Illustrative 23-EDD Keyboard

Chris Vaisvil made a do it yourself 23 edo electric guitar out of less than $50 of material. Here he is playing it.

playing.jpg

Here is a still shot of the completed instrument.

complette.jpg

This movie is a series of still shots Chris took during the process of making a 23 edo guitar in a stick like form. At the end the guitar is played without effects etc. and the open string tuning is sounded - which starts with a normal E and then adjusted to the 9th / 7th fret unison, like a typical 12edo guitar fashion.

Lumatone

See: Lumatone mapping for 23edo

Music

See also: Category:23edo tracks

Further reading

Libro_Icositrifónico.PNG
Icosikaitriphonic Scales for Guitar cover art.