38edo: Difference between revisions
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== Theory == | == Theory == | ||
Since {{nowrap| | Since 38 factors as {{nowrap|2 × 19}}, 38edo can be thought of as two parallel chains of [[19edo]]. It provides a possible correction to the [[11/1|11th harmonic]] of 19edo, which works well with 19edo's flat approximations of the [[3/1|3rd]] and [[5/1|5th]] harmonics, making it a decent [[2.3.5.11 subgroup|2.3.5.11-subgroup]] system. Compared to 19edo, the halving of the step size lowers [[consistency]], and leaves it only mediocre in terms of overall [[relative interval error|relative error]]. However, the fact that the 3rd and 5th harmonics are flat by almost exactly the same amount, while the 11th is close to double that, means there are quite a few near-perfect composite ratios, such as the the [[6/5]] it shares with 19edo, plus [[11/9]], [[15/11]], [[25/22]], and their [[octave complement]]s, while a single step nears [[55/54]]. The approximation to [[11/9]] in particular should be noted for forming a 10-strong [[consistent circle]]. This gives several interesting possibilities for unusual near-just chords such as 15:18:22:25:30. | ||
Using the [[patent val]], it [[tempering out|tempers out]] the same [[5-limit]] commas as 19edo, namely [[81/80]], [[3125/3072]] and [[15625/15552]]. In the [[7-limit]], we can add [[50/49]], and tempering out 81/80 and 50/49 gives [[injera]] temperament, for which 38 is the [[optimal patent val]] in the 7-limit. In the [[11-limit]], we can add [[121/120]] and [[176/175]], and in the [[13-limit]] we can add [[66/65]] and [[144/143]]. 38edo patently supports [[mohajira]] up to the 13-limit. While the [[7/1|7th]] and [[13/1|13th]] harmonics themselves are improved compared to 19edo, many other intervals involving these harmonics become less accurate, so whether 38edo actually corrects them is debatable. | |||
Instead, the [[val]] {{val| 38 60 88 '''106''' 131 '''140''' 155 161 }} (38df in [[wart notation]]) can be used, where the [[2.3.5.7.13 subgroup|2.3.5.13-subgroup]] mapping of 19edo is preserved, while harmonics [[11/1|11]], [[17/1|17]], and [[19/1|19]] are corrected. In 38df, every [[odd harmonic]] from 3 to 19 is characterized by a flat intonation. Furthermore, the [[mapping]]s of all [[19-odd-limit]] intervals in 38df align with their closest approximations in 38edo, except for 7/4, 13/8, and their octave complements 8/7 and 16/13, which are by definition mapped to their second-closest steps within 38df. The 38df mapping thus creates a natural full [[19-limit]] extension to the 2.3.5.7.13-subgroup mapping of 19edo. | |||
The harmonic series from 1 to 20 is approximated within 38df by the sequence: {{nowrap| 38 22 16 12 10 8 8 6 6 5 5 4 4 4 4 3 3 3 3 }} | The harmonic series from 1 to 20 is approximated within 38df by the step sequence: {{nowrap| 38 22 16 12 10 8 8 6 6 5 5 4 4 4 4 3 3 3 3 }} | ||
[[File:Harmonic_series_38df.mp3]] [[:File:Harmonic_series_38df.mp3|[Harmonic series 2-20 in 38df]]] | [[File:Harmonic_series_38df.mp3]] [[:File:Harmonic_series_38df.mp3|[Harmonic series 2-20 in 38df]]] | ||
| Line 19: | Line 19: | ||
{| class="wikitable center-1 right-2" | {| class="wikitable center-1 right-2" | ||
|- | |- | ||
! Step | ! rowspan="3" | Step | ||
! Cents | ! rowspan="3" | Cents | ||
! | ! colspan="3" | Approximated ratios | ||
! colspan="3" | [[Ups and downs notation]]* | ! rowspan="3" colspan="3" | [[Ups and downs notation]]*<br>([[Enharmonic unisons in ups and downs notation|EUs]]: vvA1 and vvd2) | ||
([[Enharmonic unisons in ups and downs notation|EUs]]: vvA1 and vvd2) | |- | ||
! rowspan="2" | Ratios of the <br>2.3.5.11.17.19 subgroup | |||
! colspan="2" | Ratios of 7 and 13 | |||
|- | |||
! Patent val | |||
! 38df val | |||
|- | |- | ||
| 0 | | 0 | ||
| 0.0 | | 0.0 | ||
| [[1/1]] | | [[1/1]] | ||
| | |||
| | |||
| Perfect 1sn | | Perfect 1sn | ||
| P1 | | P1 | ||
| Line 34: | Line 41: | ||
| 1 | | 1 | ||
| 31.6 | | 31.6 | ||
| | | | ||
| | |||
| | |||
| Up 1sn | | Up 1sn | ||
| ^1 | | ^1 | ||
| Line 41: | Line 50: | ||
| 2 | | 2 | ||
| 63.2 | | 63.2 | ||
| | | | ||
| | |||
| | |||
| Aug 1sn, dim 2nd | | Aug 1sn, dim 2nd | ||
| A1, d2 | | A1, d2 | ||
| Line 49: | Line 60: | ||
| 94.7 | | 94.7 | ||
| [[20/19]], [[19/18]], [[18/17]], [[17/16]] | | [[20/19]], [[19/18]], [[18/17]], [[17/16]] | ||
| ''[[15/14]]'' | |||
| | |||
| Upaug 1sn, downminor 2nd | | Upaug 1sn, downminor 2nd | ||
| ^A1, vm2 | | ^A1, vm2 | ||
| Line 55: | Line 68: | ||
| 4 | | 4 | ||
| 126.3 | | 126.3 | ||
| [[16/15]] | | [[16/15]] | ||
| [[14/13]] | |||
| [[15/14]], [[14/13]], [[13/12]] | |||
| Minor 2nd | | Minor 2nd | ||
| m2 | | m2 | ||
| Line 63: | Line 78: | ||
| 157.9 | | 157.9 | ||
| [[12/11]], [[11/10]] | | [[12/11]], [[11/10]] | ||
| ''[[13/12]]'' | |||
| | |||
| Mid 2nd | | Mid 2nd | ||
| ~2 | | ~2 | ||
| Line 70: | Line 87: | ||
| 189.5 | | 189.5 | ||
| [[10/9]], [[19/17]], [[9/8]] | | [[10/9]], [[19/17]], [[9/8]] | ||
| | |||
| | |||
| Major 2nd | | Major 2nd | ||
| M2 | | M2 | ||
| Line 77: | Line 96: | ||
| 221.1 | | 221.1 | ||
| [[17/15]] | | [[17/15]] | ||
| [[8/7]], ''[[15/13]]'' | |||
| | |||
| Upmajor 2nd | | Upmajor 2nd | ||
| ^M2 | | ^M2 | ||
| Line 83: | Line 104: | ||
| 8 | | 8 | ||
| 252.6 | | 252.6 | ||
| [[ | | [[22/19]] | ||
| | |||
| ''[[8/7]]'', [[15/13]], [[7/6]] | |||
| Aug 2nd, Dim 3rd | | Aug 2nd, Dim 3rd | ||
| A2, d3 | | A2, d3 | ||
| Line 90: | Line 113: | ||
| 9 | | 9 | ||
| 284.2 | | 284.2 | ||
| [[20/17]], [[ | | [[20/17]], [[19/16]] | ||
| ''[[7/6]]'' | |||
| [[13/11]] | |||
| Downminor 3rd | | Downminor 3rd | ||
| vm3 | | vm3 | ||
| Line 98: | Line 123: | ||
| 315.8 | | 315.8 | ||
| [[6/5]] | | [[6/5]] | ||
| ''[[13/11]]'', ''[[17/14]]'' | |||
| | |||
| Minor 3rd | | Minor 3rd | ||
| m3 | | m3 | ||
| Line 104: | Line 131: | ||
| 11 | | 11 | ||
| 347.4 | | 347.4 | ||
| [[ | | [[11/9]] | ||
| [[16/13]] | |||
| [[17/14]] | |||
| Mid 3rd | | Mid 3rd | ||
| ~3 | | ~3 | ||
| Line 111: | Line 140: | ||
| 12 | | 12 | ||
| 378.9 | | 378.9 | ||
| [[ | | [[5/4]] | ||
| | |||
| ''[[16/13]]'' | |||
| Major 3rd | | Major 3rd | ||
| M3 | | M3 | ||
| Line 118: | Line 149: | ||
| 13 | | 13 | ||
| 410.5 | | 410.5 | ||
| [[24/19]], [[19/15]] | | [[24/19]], [[19/15]] | ||
| ''[[9/7]]'' | |||
| [[14/11]] | |||
| Upmajor 3rd, Downdim 4th | | Upmajor 3rd, Downdim 4th | ||
| ^M3, vd4 | | ^M3, vd4 | ||
| Line 125: | Line 158: | ||
| 14 | | 14 | ||
| 442.1 | | 442.1 | ||
| [[ | | [[22/17]] | ||
| ''[[14/11]]'', ''[[17/13]]'' | |||
| [[9/7]], [[13/10]] | |||
| Aug 3rd, dim 4th | | Aug 3rd, dim 4th | ||
| A3, d4 | | A3, d4 | ||
| Line 132: | Line 167: | ||
| 15 | | 15 | ||
| 473.7 | | 473.7 | ||
| | |||
| ''[[13/10]]'' | |||
| [[17/13]] | | [[17/13]] | ||
| Down 4th | | Down 4th | ||
| Line 140: | Line 177: | ||
| 505.3 | | 505.3 | ||
| [[4/3]] | | [[4/3]] | ||
| ''[[19/14]]'' | |||
| | |||
| Perfect 4th | | Perfect 4th | ||
| P4 | | P4 | ||
| Line 146: | Line 185: | ||
| 17 | | 17 | ||
| 536.8 | | 536.8 | ||
| [[ | | [[15/11]], [[11/8]] | ||
| ''[[18/13]]'' | |||
| [[19/14]], [[26/19]] | |||
| Up 4th | | Up 4th | ||
| ^4 | | ^4 | ||
| Line 153: | Line 194: | ||
| 18 | | 18 | ||
| 568.4 | | 568.4 | ||
| | |||
| ''[[26/19]]'' | |||
| [[18/13]], [[7/5]] | | [[18/13]], [[7/5]] | ||
| Aug 4th | | Aug 4th | ||
| Line 161: | Line 204: | ||
| 600.0 | | 600.0 | ||
| [[24/17]], [[17/12]] | | [[24/17]], [[17/12]] | ||
| [[7/5]], [[10/7]] | |||
| | |||
| Upaug 4th, downdim 5th | | Upaug 4th, downdim 5th | ||
| ^A4, vd5 | | ^A4, vd5 | ||
| Line 167: | Line 212: | ||
| 20 | | 20 | ||
| 631.6 | | 631.6 | ||
| | |||
| ''[[19/13]]'' | |||
| [[10/7]], [[13/9]] | | [[10/7]], [[13/9]] | ||
| Dim 5th | | Dim 5th | ||
| Line 174: | Line 221: | ||
| 21 | | 21 | ||
| 663.2 | | 663.2 | ||
| [[16/11]], [[ | | [[16/11]], [[22/15]] | ||
| ''[[13/9]]'' | |||
| [[19/13]], [[28/19]] | |||
| Down 5th | | Down 5th | ||
| v5 | | v5 | ||
| Line 182: | Line 231: | ||
| 694.7 | | 694.7 | ||
| [[3/2]] | | [[3/2]] | ||
| ''[[28/19]]'' | |||
| | |||
| Perfect 5th | | Perfect 5th | ||
| P5 | | P5 | ||
| Line 188: | Line 239: | ||
| 23 | | 23 | ||
| 726.3 | | 726.3 | ||
| | |||
| ''[[20/13]]'' | |||
| [[26/17]] | | [[26/17]] | ||
| Up 5th | | Up 5th | ||
| Line 195: | Line 248: | ||
| 24 | | 24 | ||
| 757.9 | | 757.9 | ||
| [[ | | [[17/11]] | ||
| ''[[26/17]]'', ''[[11/7]]'' | |||
| | |||
| Aug 5th, dim 6th | | Aug 5th, dim 6th | ||
| A5, d6 | | A5, d6 | ||
| Line 202: | Line 257: | ||
| 25 | | 25 | ||
| 789.5 | | 789.5 | ||
| [[ | | [[30/19]], [[19/12]] | ||
| ''[[14/9]]'' | |||
| [[11/7]] | |||
| Upaug 5th, downminor 6th | | Upaug 5th, downminor 6th | ||
| ^A5, vm6 | | ^A5, vm6 | ||
| Line 209: | Line 266: | ||
| 26 | | 26 | ||
| 821.1 | | 821.1 | ||
| [[8/5]] | | [[8/5]] | ||
| | |||
| ''[[13/8]]'' | |||
| Minor 6th | | Minor 6th | ||
| m6 | | m6 | ||
| Line 216: | Line 275: | ||
| 27 | | 27 | ||
| 852.6 | | 852.6 | ||
| [[18/11]] | | [[18/11]] | ||
| [[13/8]] | |||
| [[28/17]] | |||
| Mid 6th | | Mid 6th | ||
| ~6 | | ~6 | ||
| Line 224: | Line 285: | ||
| 884.2 | | 884.2 | ||
| [[5/3]] | | [[5/3]] | ||
| ''[[28/17]]'', ''[[22/13]]'' | |||
| | |||
| Major 6th | | Major 6th | ||
| M6 | | M6 | ||
| Line 230: | Line 293: | ||
| 29 | | 29 | ||
| 915.8 | | 915.8 | ||
| [[32/19 | | [[32/19]], [[17/10]] | ||
| | |||
| | |||
| Upmajor 6th | | Upmajor 6th | ||
| ^M6 | | ^M6 | ||
| Line 237: | Line 302: | ||
| 30 | | 30 | ||
| 947.4 | | 947.4 | ||
| [[ | | [[19/11]] | ||
| | |||
| [[12/7]], [[26/15]], ''[[7/4]]'' | |||
| Aug 6th, dim 7th | | Aug 6th, dim 7th | ||
| A6, d7 | | A6, d7 | ||
| Line 245: | Line 312: | ||
| 978.9 | | 978.9 | ||
| [[30/17]] | | [[30/17]] | ||
| ''[[26/15]]'', [[7/4]] | |||
| | |||
| Downminor 7th | | Downminor 7th | ||
| vm7 | | vm7 | ||
| Line 252: | Line 321: | ||
| 1010.5 | | 1010.5 | ||
| [[16/9]], [[34/19]], [[9/5]] | | [[16/9]], [[34/19]], [[9/5]] | ||
| | |||
| | |||
| Minor 7th | | Minor 7th | ||
| m7 | | m7 | ||
| Line 259: | Line 330: | ||
| 1042.1 | | 1042.1 | ||
| [[20/11]], [[11/6]] | | [[20/11]], [[11/6]] | ||
| ''[[24/13]]'' | |||
| | |||
| Mid 7th | | Mid 7th | ||
| ~7 | | ~7 | ||
| Line 265: | Line 338: | ||
| 34 | | 34 | ||
| 1073.7 | | 1073.7 | ||
| [[ | | [[15/8]] | ||
| [[13/7]] | |||
| [[24/13]], [[13/7]], [[28/15]] | |||
| Major 7th | | Major 7th | ||
| M7 | | M7 | ||
| Line 273: | Line 348: | ||
| 1105.3 | | 1105.3 | ||
| [[32/17]], [[17/9]], [[36/19]], [[19/10]] | | [[32/17]], [[17/9]], [[36/19]], [[19/10]] | ||
| ''[[28/15]]'' | |||
| | |||
| Upmajor 7th, Downdim 8ve | | Upmajor 7th, Downdim 8ve | ||
| ^M7, vd8 | | ^M7, vd8 | ||
| Line 279: | Line 356: | ||
| 36 | | 36 | ||
| 1136.8 | | 1136.8 | ||
| | | | ||
| | |||
| | |||
| Aug 7th, dim 8ve | | Aug 7th, dim 8ve | ||
| A7, d8 | | A7, d8 | ||
| Line 287: | Line 366: | ||
| 1168.4 | | 1168.4 | ||
| | | | ||
| | |||
| | |||
| Down 8ve | | Down 8ve | ||
| v8 | | v8 | ||
| Line 294: | Line 375: | ||
| 1200.0 | | 1200.0 | ||
| [[2/1]] | | [[2/1]] | ||
| | |||
| | |||
| Perfect 8ve | | Perfect 8ve | ||
| P8 | | P8 | ||
Latest revision as of 17:55, 30 May 2026
| ← 37edo | 38edo | 39edo → |
38 equal divisions of the octave (abbreviated 38edo or 38ed2), also called 38-tone equal temperament (38tet) or 38 equal temperament (38et) when viewed under a regular temperament perspective, is the tuning system that divides the octave into 38 equal parts of about 31.6 ¢ each. Each step represents a frequency ratio of 21/38, or the 38th root of 2.
Theory
Since 38 factors as 2 × 19, 38edo can be thought of as two parallel chains of 19edo. It provides a possible correction to the 11th harmonic of 19edo, which works well with 19edo's flat approximations of the 3rd and 5th harmonics, making it a decent 2.3.5.11-subgroup system. Compared to 19edo, the halving of the step size lowers consistency, and leaves it only mediocre in terms of overall relative error. However, the fact that the 3rd and 5th harmonics are flat by almost exactly the same amount, while the 11th is close to double that, means there are quite a few near-perfect composite ratios, such as the the 6/5 it shares with 19edo, plus 11/9, 15/11, 25/22, and their octave complements, while a single step nears 55/54. The approximation to 11/9 in particular should be noted for forming a 10-strong consistent circle. This gives several interesting possibilities for unusual near-just chords such as 15:18:22:25:30.
Using the patent val, it tempers out the same 5-limit commas as 19edo, namely 81/80, 3125/3072 and 15625/15552. In the 7-limit, we can add 50/49, and tempering out 81/80 and 50/49 gives injera temperament, for which 38 is the optimal patent val in the 7-limit. In the 11-limit, we can add 121/120 and 176/175, and in the 13-limit we can add 66/65 and 144/143. 38edo patently supports mohajira up to the 13-limit. While the 7th and 13th harmonics themselves are improved compared to 19edo, many other intervals involving these harmonics become less accurate, so whether 38edo actually corrects them is debatable.
Instead, the val ⟨38 60 88 106 131 140 155 161] (38df in wart notation) can be used, where the 2.3.5.13-subgroup mapping of 19edo is preserved, while harmonics 11, 17, and 19 are corrected. In 38df, every odd harmonic from 3 to 19 is characterized by a flat intonation. Furthermore, the mappings of all 19-odd-limit intervals in 38df align with their closest approximations in 38edo, except for 7/4, 13/8, and their octave complements 8/7 and 16/13, which are by definition mapped to their second-closest steps within 38df. The 38df mapping thus creates a natural full 19-limit extension to the 2.3.5.7.13-subgroup mapping of 19edo.
The harmonic series from 1 to 20 is approximated within 38df by the step sequence: 38 22 16 12 10 8 8 6 6 5 5 4 4 4 4 3 3 3 3
[Harmonic series 2-20 in 38df]
Prime harmonics
| Harmonic | 2 | 3 | 5 | 7 | 11 | 13 | 17 | 19 | 23 | 29 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Error | Absolute (¢) | +0.0 | -7.2 | -7.4 | +10.1 | -14.5 | +12.1 | -10.2 | -13.3 | +3.3 | +12.5 | -8.2 |
| Relative (%) | +0.0 | -22.9 | -23.3 | +32.1 | -45.8 | +38.3 | -32.4 | -42.1 | +10.5 | +39.7 | -25.9 | |
| Steps (reduced) |
38 (0) |
60 (22) |
88 (12) |
107 (31) |
131 (17) |
141 (27) |
155 (3) |
161 (9) |
172 (20) |
185 (33) |
188 (36) | |
Intervals
| Step | Cents | Approximated ratios | Ups and downs notation* (EUs: vvA1 and vvd2) | ||||
|---|---|---|---|---|---|---|---|
| Ratios of the 2.3.5.11.17.19 subgroup |
Ratios of 7 and 13 | ||||||
| Patent val | 38df val | ||||||
| 0 | 0.0 | 1/1 | Perfect 1sn | P1 | D | ||
| 1 | 31.6 | Up 1sn | ^1 | ^D | |||
| 2 | 63.2 | Aug 1sn, dim 2nd | A1, d2 | D# | |||
| 3 | 94.7 | 20/19, 19/18, 18/17, 17/16 | 15/14 | Upaug 1sn, downminor 2nd | ^A1, vm2 | ^D#, vEb | |
| 4 | 126.3 | 16/15 | 14/13 | 15/14, 14/13, 13/12 | Minor 2nd | m2 | Eb |
| 5 | 157.9 | 12/11, 11/10 | 13/12 | Mid 2nd | ~2 | vE | |
| 6 | 189.5 | 10/9, 19/17, 9/8 | Major 2nd | M2 | E | ||
| 7 | 221.1 | 17/15 | 8/7, 15/13 | Upmajor 2nd | ^M2 | ^E | |
| 8 | 252.6 | 22/19 | 8/7, 15/13, 7/6 | Aug 2nd, Dim 3rd | A2, d3 | E#, Fb | |
| 9 | 284.2 | 20/17, 19/16 | 7/6 | 13/11 | Downminor 3rd | vm3 | vF |
| 10 | 315.8 | 6/5 | 13/11, 17/14 | Minor 3rd | m3 | F | |
| 11 | 347.4 | 11/9 | 16/13 | 17/14 | Mid 3rd | ~3 | ^F |
| 12 | 378.9 | 5/4 | 16/13 | Major 3rd | M3 | F# | |
| 13 | 410.5 | 24/19, 19/15 | 9/7 | 14/11 | Upmajor 3rd, Downdim 4th | ^M3, vd4 | ^F#, vGb |
| 14 | 442.1 | 22/17 | 14/11, 17/13 | 9/7, 13/10 | Aug 3rd, dim 4th | A3, d4 | Gb |
| 15 | 473.7 | 13/10 | 17/13 | Down 4th | v4 | vG | |
| 16 | 505.3 | 4/3 | 19/14 | Perfect 4th | P4 | G | |
| 17 | 536.8 | 15/11, 11/8 | 18/13 | 19/14, 26/19 | Up 4th | ^4 | ^G |
| 18 | 568.4 | 26/19 | 18/13, 7/5 | Aug 4th | A4 | G# | |
| 19 | 600.0 | 24/17, 17/12 | 7/5, 10/7 | Upaug 4th, downdim 5th | ^A4, vd5 | ^G#, vAb | |
| 20 | 631.6 | 19/13 | 10/7, 13/9 | Dim 5th | d5 | Ab | |
| 21 | 663.2 | 16/11, 22/15 | 13/9 | 19/13, 28/19 | Down 5th | v5 | vA |
| 22 | 694.7 | 3/2 | 28/19 | Perfect 5th | P5 | A | |
| 23 | 726.3 | 20/13 | 26/17 | Up 5th | ^5 | ^A | |
| 24 | 757.9 | 17/11 | 26/17, 11/7 | Aug 5th, dim 6th | A5, d6 | A# | |
| 25 | 789.5 | 30/19, 19/12 | 14/9 | 11/7 | Upaug 5th, downminor 6th | ^A5, vm6 | ^A#, vBb |
| 26 | 821.1 | 8/5 | 13/8 | Minor 6th | m6 | Bb | |
| 27 | 852.6 | 18/11 | 13/8 | 28/17 | Mid 6th | ~6 | vB |
| 28 | 884.2 | 5/3 | 28/17, 22/13 | Major 6th | M6 | B | |
| 29 | 915.8 | 32/19, 17/10 | Upmajor 6th | ^M6 | ^B | ||
| 30 | 947.4 | 19/11 | 12/7, 26/15, 7/4 | Aug 6th, dim 7th | A6, d7 | B#, Cb | |
| 31 | 978.9 | 30/17 | 26/15, 7/4 | Downminor 7th | vm7 | vC | |
| 32 | 1010.5 | 16/9, 34/19, 9/5 | Minor 7th | m7 | C | ||
| 33 | 1042.1 | 20/11, 11/6 | 24/13 | Mid 7th | ~7 | ^C | |
| 34 | 1073.7 | 15/8 | 13/7 | 24/13, 13/7, 28/15 | Major 7th | M7 | C# |
| 35 | 1105.3 | 32/17, 17/9, 36/19, 19/10 | 28/15 | Upmajor 7th, Downdim 8ve | ^M7, vd8 | ^C#, vDb | |
| 36 | 1136.8 | Aug 7th, dim 8ve | A7, d8 | Db | |||
| 37 | 1168.4 | Down 8ve | v8 | vD | |||
| 38 | 1200.0 | 2/1 | Perfect 8ve | P8 | D | ||
* Ups and downs may be substituted with semi-sharps and semi-flats, respectively
Notation
Ups and downs notation
Spoken as up, sharp, upsharp, etc. Note that up can be respelled as downsharp.
Quarter-tone notation
Since a sharp raises by two steps, quarter-tone accidentals can also be used:
| Step offset | −4 | −3 | −2 | −1 | 0 | +1 | +2 | +3 | +4 |
|---|---|---|---|---|---|---|---|---|---|
| Symbol | |
|
|
|
|
|
|
|
|
Sagittal notation
This notation uses the same sagittal sequence as EDOs 17, 24, and 31, is a subset of the notation for 76-EDO, and is a superset of the notation for 19-EDO.
Evo flavor

Revo flavor

Evo-SZ flavor

Because it contains no Sagittal symbols, this Evo-SZ Sagittal notation is also a Stein-Zimmerman notation.
Approximation to JI
Interval mappings
The following tables show how 15-odd-limit intervals are represented in 38edo. Prime harmonics are in bold; inconsistent intervals are in italics.
| Interval and complement | Error (abs, ¢) | Error (rel, %) |
|---|---|---|
| 1/1, 2/1 | 0.000 | 0.0 |
| 11/9, 18/11 | 0.040 | 0.1 |
| 15/11, 22/15 | 0.109 | 0.3 |
| 5/3, 6/5 | 0.148 | 0.5 |
| 13/7, 14/13 | 1.982 | 6.3 |
| 15/13, 26/15 | 4.891 | 15.5 |
| 13/11, 22/13 | 4.999 | 15.8 |
| 13/9, 18/13 | 5.039 | 16.0 |
| 15/14, 28/15 | 6.873 | 21.8 |
| 11/7, 14/11 | 6.982 | 22.1 |
| 9/7, 14/9 | 7.021 | 22.2 |
| 9/5, 10/9 | 7.070 | 22.4 |
| 11/10, 20/11 | 7.109 | 22.5 |
| 3/2, 4/3 | 7.218 | 22.9 |
| 11/6, 12/11 | 7.258 | 23.0 |
| 5/4, 8/5 | 7.366 | 23.3 |
| 7/4, 8/7 | 10.121 | 32.1 |
| 13/8, 16/13 | 12.104 | 38.3 |
| 13/10, 20/13 | 12.109 | 38.3 |
| 13/12, 24/13 | 12.257 | 38.8 |
| 7/5, 10/7 | 14.091 | 44.6 |
| 7/6, 12/7 | 14.239 | 45.1 |
| 9/8, 16/9 | 14.436 | 45.7 |
| 11/8, 16/11 | 14.476 | 45.8 |
| 15/8, 16/15 | 14.585 | 46.2 |
| Interval and complement | Error (abs, ¢) | Error (rel, %) |
|---|---|---|
| 1/1, 2/1 | 0.000 | 0.0 |
| 11/9, 18/11 | 0.040 | 0.1 |
| 15/11, 22/15 | 0.109 | 0.3 |
| 5/3, 6/5 | 0.148 | 0.5 |
| 13/7, 14/13 | 1.982 | 6.3 |
| 9/5, 10/9 | 7.070 | 22.4 |
| 11/10, 20/11 | 7.109 | 22.5 |
| 3/2, 4/3 | 7.218 | 22.9 |
| 11/6, 12/11 | 7.258 | 23.0 |
| 5/4, 8/5 | 7.366 | 23.3 |
| 7/4, 8/7 | 10.121 | 32.1 |
| 13/8, 16/13 | 12.104 | 38.3 |
| 9/8, 16/9 | 14.436 | 45.7 |
| 11/8, 16/11 | 14.476 | 45.8 |
| 15/8, 16/15 | 14.585 | 46.2 |
| 7/6, 12/7 | 17.340 | 54.9 |
| 7/5, 10/7 | 17.488 | 55.4 |
| 13/12, 24/13 | 19.322 | 61.2 |
| 13/10, 20/13 | 19.470 | 61.7 |
| 9/7, 14/9 | 24.558 | 77.8 |
| 11/7, 14/11 | 24.597 | 77.9 |
| 15/14, 28/15 | 24.706 | 78.2 |
| 13/9, 18/13 | 26.540 | 84.0 |
| 13/11, 22/13 | 26.580 | 84.2 |
| 15/13, 26/15 | 26.688 | 84.5 |
| Interval and complement | Error (abs, ¢) | Error (rel, %) |
|---|---|---|
| 1/1, 2/1 | 0.000 | 0.0 |
| 11/9, 18/11 | 0.040 | 0.1 |
| 15/11, 22/15 | 0.109 | 0.3 |
| 5/3, 6/5 | 0.148 | 0.5 |
| 13/7, 14/13 | 1.982 | 6.3 |
| 15/13, 26/15 | 4.891 | 15.5 |
| 13/11, 22/13 | 4.999 | 15.8 |
| 13/9, 18/13 | 5.039 | 16.0 |
| 15/14, 28/15 | 6.873 | 21.8 |
| 11/7, 14/11 | 6.982 | 22.1 |
| 9/7, 14/9 | 7.021 | 22.2 |
| 9/5, 10/9 | 7.070 | 22.4 |
| 11/10, 20/11 | 7.109 | 22.5 |
| 3/2, 4/3 | 7.218 | 22.9 |
| 11/6, 12/11 | 7.258 | 23.0 |
| 5/4, 8/5 | 7.366 | 23.3 |
| 13/10, 20/13 | 12.109 | 38.3 |
| 13/12, 24/13 | 12.257 | 38.8 |
| 7/5, 10/7 | 14.091 | 44.6 |
| 7/6, 12/7 | 14.239 | 45.1 |
| 9/8, 16/9 | 14.436 | 45.7 |
| 11/8, 16/11 | 14.476 | 45.8 |
| 15/8, 16/15 | 14.585 | 46.2 |
| 13/8, 16/13 | 19.475 | 61.7 |
| 7/4, 8/7 | 21.457 | 67.9 |
Rank-2 temperaments
| Temperament | Generator | Periods per octave |
|---|---|---|
| Opossum | 5\38 | 1 |
| Hemisensi | 7\38 | 1 |
| Delorean / subkla | 9\38 | 1 |
| Migration / mohajira / nethertone / ptolemy / subklei | 11\38 | 1 |
| Hocus | 13\38 | 1 |
| Buzzard | 15\38 | 1 |
| Maquila / wilsec | 17\38 | 1 |
| Bimeantone / injera | 3\38 | 2 |
| Bison / hemikleismic | 5\38 | 2 |
| Astrology / divination / horoscope | 7\38 | 2 |
| Decimal | 8\38 | 2 |
Octave stretch or compression
38edo's approximation of JI can be improved by slightly stretching the octave, as in 88ed5, 166zpi or 60edt.
Scales
- Astrology[22]: 2 1 2 2 2 1 2 2 2 1 2 2 1 2 2 2 1 2 2 2 1 2
- Buzzard[8]: 7 1 7 7 1 7 1 7
- Buzzard[13] 1 6 1 6 1 1 6 1 1 6 1 6 1
- Buzzard[18]: 1 5 1 1 1 5 1 1 1 5 1 1 5 1 1 1 5 1
- Buzzard[23]: 1 1 4 1 1 1 4 1 1 1 1 4 1 1 1 1 4 1 1 1 4 1 1
- Decimal[10]: 3 5 3 5 3 3 5 3 5 3
- Decimal[14]: 3 2 3 3 3 2 3 3 2 3 3 3 2 3
- Decimal[24]: 2 1 2 1 2 2 1 2 1 2 1 2 2 1 2 1 2 2 1 2 1 2 1 2
- Hocus[23]: 1 1 1 6 1 1 1 1 1 1 1 6 1 1 1 1 1 1 1 6 1 1 1
- Injera[6]: 3 13 3 3 13 3
- Injera[8]: 3 3 10 3 3 3 10 3
- Injera[10]: 3 3 7 3 3 3 3 7 3 3
- Injera[12]: 3 3 3 4 3 3 3 3 3 4 3 3
- Injera[14]: 3 3 3 1 3 3 3 3 3 3 1 3 3 3
- Injera[26]: 1 2 1 2 1 2 1 2 1 2 1 2 1 1 2 1 2 1 2 1 2 1 2 1 2 1
- Maquila[20]: 1 3 1 3 1 3 1 3 1 1 3 1 3 1 3 1 3 1 3 1
- Mohajira[7] (a.k.a. quasi-equiheptatonic): 5 6 5 6 5 6 5
- Mohajira[10]: 5 1 5 5 1 5 5 5 1 5
- Mohajira[17]: 1 4 1 4 1 1 4 1 4 1 4 1 1 4 1 4 1
- Mohajira[24]: 1 3 1 1 1 3 1 1 3 1 1 1 3 1 1 3 1 1 3 1 1 1 3 1
- Subkla[13]: 2 5 2 2 5 2 2 2 5 2 2 5 2
- Subkla[17]: 2 3 2 2 2 3 2 2 2 3 2 2 2 3 2 2
- Subkla[21]: 2 2 1 2 2 2 2 1 2 2 2 2 2 1 2 2 2 2 1 2 2
- MOS subsets
- of injera[12]
- Quasi-major: 6 7 3 6 6 7 3
- Quasi-minor: 6 3 7 6 3 7 6
| This article or section contains multiple idiosyncratic terms. Such terms are used by only a few people and are not regularly used within the community. |
- of bison[22]
- Tame bison: 3 1 1 1 1 3 3 1 1 1 3 3 1 1 1 3 3 1 1 1 1 3
- of hemisensi[11]
- Hemisettled11: 3 3 3 4 3 6 3 3 3 4 3
- of hemisensi[16]
- Hemisettled16: 5 1 3 3 1 3 1 1 3 1 5 1 3 3 1 3
- of opossum[23]
- Tame possum: 3 3 2 2 2 3 2 2 2 3 2 2 2 3 3
- Others
| This article or section contains multiple idiosyncratic terms. Such terms are used by only a few people and are not regularly used within the community. |
- Antipental blues: 9 7 2 4 9 7
- Ninteenplus: 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1 1 2 2 2
- Quasi-equipentatonic: 8 8 6 8 8
- Well-tempered 19-in-38: 2 2 2 2 2 2 2 2 2 2 2 2 2 2 3 1 2 2 2
Instruments
Music
- Spirit of the Night - Secret of Mana (microtonal cover in 38edo) (2025)
- 38edo improv (2025)
- waltz in 38edo (2026)
- [short] (demonstrates Lumatone mapping)
- [full version]








