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== Theory ==
== Theory ==
Since {{nowrap|38 {{=}} 2 × 19}}, it can be thought of as two parallel [[19edo]]s. While the halving of the step size lowers [[consistency]] and leaves it only mediocre in terms of overall [[relative interval error|relative error]], the fact that the 3rd and 5th harmonics are flat by almost exactly the same amount, while the 11th is 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 inversions) 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.  
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 [[Warts|38df]] mapping, every [[prime interval]] from 3 to 19 is characterized by a flat intonation. Furthermore, the [[mapping]] of all [[19-odd-limit]] intervals in 38df aligns with their closest approximations in 38edo, excepting for 7/4 and 13/8, along with their octave complements 8/7 and 16/13, which are by definition mapped to their secondary optimal steps within 38df. In other words, all 19-odd-limit intervals are [[consistency|consistent]] within the 38df [[val]] {{val| 38 60 88 106 131 140 155 161 }}.  
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.


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 }}
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 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]]]
=== RTT ===
''See [[regular temperament]] for more about what all this means and how to use it.''
38edo [[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 [[11-limit]], we can add 121/120 and 176/175.


=== Prime harmonics ===
=== Prime harmonics ===
Line 22: Line 19:
{| class="wikitable center-1 right-2"
{| class="wikitable center-1 right-2"
|-
|-
! Step
! rowspan="3" | Step
! Cents
! rowspan="3" | Cents
! 19-odd-limit ratios,<br>in 38df val
! 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)
|-
! 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]]
|
|  
| Perfect 1sn
| Perfect 1sn
| P1
| P1
Line 36: Line 41:
| 1
| 1
| 31.6
| 31.6
|
|
|
|  
| Up 1sn
| Up 1sn
| ^1
| ^1
Line 43: Line 50:
| 2
| 2
| 63.2
| 63.2
|
|
|
|  
| Aug 1sn, dim 2nd
| Aug 1sn, dim 2nd
| A1, d2
| A1, d2
Line 51: 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 57: Line 68:
| 4
| 4
| 126.3
| 126.3
| [[16/15]], [[15/14]], [[14/13]], [[13/12]]
| [[16/15]]
| [[14/13]]
| [[15/14]], [[14/13]], [[13/12]]
| Minor 2nd
| Minor 2nd
| m2
| m2
Line 65: Line 78:
| 157.9
| 157.9
| [[12/11]], [[11/10]]
| [[12/11]], [[11/10]]
| ''[[13/12]]''
|
| Mid 2nd
| Mid 2nd
| ~2
| ~2
Line 72: 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 79: Line 96:
| 221.1
| 221.1
| [[17/15]]
| [[17/15]]
| [[8/7]], ''[[15/13]]''
|
| Upmajor 2nd
| Upmajor 2nd
| ^M2
| ^M2
Line 85: Line 104:
| 8
| 8
| 252.6
| 252.6
| [[8/7]], [[15/13]], [[22/19]], [[7/6]]
| [[22/19]]
|
| ''[[8/7]]'', [[15/13]], [[7/6]]
| Aug 2nd, Dim 3rd
| Aug 2nd, Dim 3rd
| A2, d3
| A2, d3
Line 92: Line 113:
| 9
| 9
| 284.2
| 284.2
| [[20/17]], [[13/11]], [[19/16]]
| [[20/17]], [[19/16]]
| ''[[7/6]]''
| [[13/11]]
| Downminor 3rd
| Downminor 3rd
| vm3
| vm3
Line 100: Line 123:
| 315.8
| 315.8
| [[6/5]]
| [[6/5]]
| ''[[13/11]]'', ''[[17/14]]''
|
| Minor 3rd
| Minor 3rd
| m3
| m3
Line 106: Line 131:
| 11
| 11
| 347.4
| 347.4
| [[17/14]], [[11/9]]
| [[11/9]]
| [[16/13]]
| [[17/14]]
| Mid 3rd
| Mid 3rd
| ~3
| ~3
Line 113: Line 140:
| 12
| 12
| 378.9
| 378.9
| [[16/13]], [[5/4]]
| [[5/4]]
|
| ''[[16/13]]''
| Major 3rd
| Major 3rd
| M3
| M3
Line 120: Line 149:
| 13
| 13
| 410.5
| 410.5
| [[24/19]], [[19/15]], [[14/11]]
| [[24/19]], [[19/15]]
| ''[[9/7]]''
| [[14/11]]
| Upmajor 3rd, Downdim 4th
| Upmajor 3rd, Downdim 4th
| ^M3, vd4
| ^M3, vd4
Line 127: Line 158:
| 14
| 14
| 442.1
| 442.1
| [[9/7]], [[22/17]], [[13/10]]
| [[22/17]]
| ''[[14/11]]'', ''[[17/13]]''
| [[9/7]], [[13/10]]
| Aug 3rd, dim 4th
| Aug 3rd, dim 4th
| A3, d4
| A3, d4
Line 134: Line 167:
| 15
| 15
| 473.7
| 473.7
|
| ''[[13/10]]''
| [[17/13]]
| [[17/13]]
| Down 4th
| Down 4th
Line 142: Line 177:
| 505.3
| 505.3
| [[4/3]]
| [[4/3]]
| ''[[19/14]]''
|
| Perfect 4th
| Perfect 4th
| P4
| P4
Line 148: Line 185:
| 17
| 17
| 536.8
| 536.8
| [[19/14]], [[15/11]], [[26/19]], [[11/8]]
| [[15/11]], [[11/8]]
| ''[[18/13]]''
| [[19/14]], [[26/19]]
| Up 4th
| Up 4th
| ^4
| ^4
Line 155: Line 194:
| 18
| 18
| 568.4
| 568.4
|
| ''[[26/19]]''
| [[18/13]], [[7/5]]
| [[18/13]], [[7/5]]
| Aug 4th
| Aug 4th
Line 163: 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 169: Line 212:
| 20
| 20
| 631.6
| 631.6
|
| ''[[19/13]]''
| [[10/7]], [[13/9]]
| [[10/7]], [[13/9]]
| Dim 5th
| Dim 5th
Line 176: Line 221:
| 21
| 21
| 663.2
| 663.2
| [[16/11]], [[19/13]], [[22/15]], [[28/19]]
| [[16/11]], [[22/15]]
| ''[[13/9]]''
| [[19/13]], [[28/19]]
| Down 5th
| Down 5th
| v5
| v5
Line 184: Line 231:
| 694.7
| 694.7
| [[3/2]]
| [[3/2]]
| ''[[28/19]]''
|
| Perfect 5th
| Perfect 5th
| P5
| P5
Line 190: Line 239:
| 23
| 23
| 726.3
| 726.3
|
| ''[[20/13]]''
| [[26/17]]
| [[26/17]]
| Up 5th
| Up 5th
Line 197: Line 248:
| 24
| 24
| 757.9
| 757.9
| [[20/13]], [[17/11]], [[14/9]]
| [[17/11]]
| ''[[26/17]]'', ''[[11/7]]''
|
| Aug 5th, dim 6th
| Aug 5th, dim 6th
| A5, d6
| A5, d6
Line 204: Line 257:
| 25
| 25
| 789.5
| 789.5
| [[11/7]], [[30/19]], [[19/12]]
| [[30/19]], [[19/12]]
| ''[[14/9]]''
| [[11/7]]
| Upaug 5th, downminor 6th
| Upaug 5th, downminor 6th
| ^A5, vm6
| ^A5, vm6
Line 211: Line 266:
| 26
| 26
| 821.1
| 821.1
| [[8/5]], [[13/8]]
| [[8/5]]
|
| ''[[13/8]]''
| Minor 6th
| Minor 6th
| m6
| m6
Line 218: Line 275:
| 27
| 27
| 852.6
| 852.6
| [[18/11]], [[28/17]]
| [[18/11]]
| [[13/8]]
| [[28/17]]
| Mid 6th
| Mid 6th
| ~6
| ~6
Line 226: Line 285:
| 884.2
| 884.2
| [[5/3]]
| [[5/3]]
| ''[[28/17]]'', ''[[22/13]]''
|
| Major 6th
| Major 6th
| M6
| M6
Line 232: Line 293:
| 29
| 29
| 915.8
| 915.8
| [[32/19]], [[22/13]], [[17/10]]
| [[32/19]], [[17/10]]
|
|
| Upmajor 6th
| Upmajor 6th
| ^M6
| ^M6
Line 239: Line 302:
| 30
| 30
| 947.4
| 947.4
| [[12/7]], [[19/11]], [[26/15]], [[7/4]]
| [[19/11]]
|
| [[12/7]], [[26/15]], ''[[7/4]]''
| Aug 6th, dim 7th
| Aug 6th, dim 7th
| A6, d7
| A6, d7
Line 247: Line 312:
| 978.9
| 978.9
| [[30/17]]
| [[30/17]]
| ''[[26/15]]'', [[7/4]]
|
| Downminor 7th
| Downminor 7th
| vm7
| vm7
Line 254: 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 261: Line 330:
| 1042.1
| 1042.1
| [[20/11]], [[11/6]]
| [[20/11]], [[11/6]]
| ''[[24/13]]''
|
| Mid 7th
| Mid 7th
| ~7
| ~7
Line 267: Line 338:
| 34
| 34
| 1073.7
| 1073.7
| [[24/13]], [[13/7]], [[28/15]], [[15/8]]
| [[15/8]]
| [[13/7]]
| [[24/13]], [[13/7]], [[28/15]]
| Major 7th
| Major 7th
| M7
| M7
Line 275: 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 281: Line 356:
| 36
| 36
| 1136.8
| 1136.8
|
|
|
|  
| Aug 7th, dim 8ve
| Aug 7th, dim 8ve
| A7, d8
| A7, d8
Line 289: Line 366:
| 1168.4
| 1168.4
|
|
|
|
| Down 8ve
| Down 8ve
| v8
| v8
Line 295: Line 374:
| 38
| 38
| 1200.0
| 1200.0
|
| [[2/1]]
|
|  
| Perfect 8ve
| Perfect 8ve
| P8
| P8
Line 305: Line 386:
=== Ups and downs notation ===
=== Ups and downs notation ===
Spoken as up, sharp, upsharp, etc. Note that up can be respelled as downsharp.
Spoken as up, sharp, upsharp, etc. Note that up can be respelled as downsharp.
{{sharpness-sharp2a}}
{{Ups and downs sharpness}}


=== Quarter-tone notation ===
=== Quarter-tone notation ===
Line 347: Line 428:


== Approximation to JI ==
== Approximation to JI ==
=== Zeta peak index ===
=== Interval mappings ===
{{ZPI
{{Q-odd-limit intervals}}
| zpi = 166
{{Q-odd-limit intervals|37.9|apx=val|header=none|tag=none|title=15-odd-limit intervals by 38df val mapping}}
| steps = 37.8901105027757
 
| step size = 31.6705331305933
== Rank-2 temperaments ==
| tempered height = 5.808723
{| class="wikitable"
| pure height = 1.330027
|+ [[Rank-2 temperament]]s in 38edo
| integral = 0.986660
|-
| gap = 15.046792
! Temperament !! Generator !! Periods per octave
| octave = 1203.48025896255
|-
| consistent = 6
| [[Opossum]] || 5\38 || 1
| distinct = 6
|-
}}
| [[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 [[octave stretch|stretching the octave]], as in [[ed5|88ed5]], [[zpi|166zpi]] or [[60edt]].
 
== Scales ==
; [[MOS scale]]s
* 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
 
; [[MODMOS|MODMOS scales]]
{{Idiosyncratic terms}}
* ''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
{{Idiosyncratic terms}}
* [[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 temperament|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 ==
== Instruments ==
Line 366: Line 521:


== Music ==
== Music ==
* [https://www.youtube.com/watch?v=Cw1Cz1ojoSw Canon at the Semitone on The Mother's Malison Theme for Cor Anglais and Violin] by [[Claudi Meneghin]]
; [[Bryan Deister]]
* [https://www.youtube.com/shorts/rewy-32BfRs ''Spirit of the Night - Secret of Mana (microtonal cover in 38edo)''] (2025)
* [https://www.youtube.com/shorts/QcFEW45uxHY ''38edo improv''] (2025)
* ''waltz in 38edo'' (2026)
** [https://www.youtube.com/shorts/Gdx4hk7FKU0 <nowiki>[short]</nowiki>] (demonstrates Lumatone mapping)
** [https://www.youtube.com/watch?v=amukQrZuseY <nowiki>[full version]</nowiki>]
 
; [[Claudi Meneghin]]
* [https://www.youtube.com/watch?v=Cw1Cz1ojoSw Canon at the Semitone on The Mother's Malison Theme for Cor Anglais and Violin] (2022)


[[Category:38edo| ]]  <!-- Main article -->
[[Category:38edo| ]]  <!-- Main article -->
[[Category:Equal divisions of the octave|##]] <!-- 2-digit number -->
[[Category:Equal divisions of the octave|##]] <!-- 2-digit number -->
[[Category:Listen]]
[[Category:Listen]]
[[Category:Todo:add rank 2 temperaments table]]

Latest revision as of 17:55, 30 May 2026

← 37edo 38edo 39edo →
Prime factorization 2 × 19
Step size 31.5789 ¢ 
Fifth 22\38 (694.737 ¢) (→ 11\19)
Semitones (A1:m2) 2:4 (63.16 ¢ : 126.3 ¢)
Consistency limit 5
Distinct consistency limit 5

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

Approximation of prime harmonics in 38edo
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.

Step offset 0 1 2 3 4 5
Sharp symbol   
 
  
   
  
   
Flat symbol
 
  
   
  
   

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

Sagittal notationPeriodic table of EDOs with sagittal notation33/32

Revo flavor

Sagittal notationPeriodic table of EDOs with sagittal notation33/32

Evo-SZ flavor

Sagittal notationPeriodic table of EDOs with sagittal notation33/32

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.

15-odd-limit intervals in 38edo (direct approximation, even if inconsistent)
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
15-odd-limit intervals in 38edo (patent val mapping)
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
15-odd-limit intervals by 38df val mapping
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

Rank-2 temperaments in 38edo
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

MOS 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
MODMOS scales
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.

Instruments

Music

Bryan Deister
Claudi Meneghin
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