38edo: Difference between revisions
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{{EDO intro|38}} | {{EDO intro|38}} | ||
==Theory== | == Theory == | ||
Since 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_errors_of_small_EDOs|relative error]], the fact that the 3rd & 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]]. This gives several interesting possibilities for unusual near-just chords such as 15:18:22:25:30. 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 [[11-limit]], we can add 121/120 and 176/175. | Since 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_errors_of_small_EDOs|relative error]], the fact that the 3rd & 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]]. This gives several interesting possibilities for unusual near-just chords such as 15:18:22:25:30. 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 [[11-limit]], we can add 121/120 and 176/175. | ||
Line 14: | Line 14: | ||
== Intervals == | == Intervals == | ||
{| class="wikitable center-1 right-2" | {| class="wikitable center-1 right-2" | ||
|- | |- | ||
! Step | ! Step | ||
! Cents | ! Cents | ||
!19-odd-limit ratios, | ! 19-odd-limit ratios,<br />treated as 38df | ||
treated as 38df | |||
! colspan="3" | [[Ups and Downs Notation]]* | ! colspan="3" | [[Ups and Downs Notation]]* | ||
|- | |- | ||
| 0 | | 0 | ||
| 0.0000 | | 0.0000 | ||
| Perfect 1sn | | Perfect 1sn | ||
| P1 | | P1 | ||
Line 32: | Line 29: | ||
| 1 | | 1 | ||
| 31.5789 | | 31.5789 | ||
| Up 1sn | | Up 1sn | ||
| ^1 | | ^1 | ||
Line 39: | Line 35: | ||
| 2 | | 2 | ||
| 63.1579 | | 63.1579 | ||
| Aug 1sn, dim 2nd | | Aug 1sn, dim 2nd | ||
| A1, d2 | | A1, d2 | ||
Line 46: | Line 41: | ||
| 3 | | 3 | ||
| 94.7368 | | 94.7368 | ||
|[[20/19]], [[19/18]], [[18/17]], [[17/16]] | | [[20/19]], [[19/18]], [[18/17]], [[17/16]] | ||
| Upaug 1sn, downminor 2nd | | Upaug 1sn, downminor 2nd | ||
| ^A1, vm2 | | ^A1, vm2 | ||
Line 53: | Line 48: | ||
| 4 | | 4 | ||
| 126.3157 | | 126.3157 | ||
|[[16/15]], [[15/14]], [[14/13]], [[13/12]] | | [[16/15]], [[15/14]], [[14/13]], [[13/12]] | ||
| Minor 2nd | | Minor 2nd | ||
| m2 | | m2 | ||
Line 60: | Line 55: | ||
| 5 | | 5 | ||
| 157.8947 | | 157.8947 | ||
|[[12/11]], [[11/10]] | | [[12/11]], [[11/10]] | ||
| Mid 2nd | | Mid 2nd | ||
| ~2 | | ~2 | ||
Line 67: | Line 62: | ||
| 6 | | 6 | ||
| 189.4737 | | 189.4737 | ||
|[[10/9]], [[19/17]], [[9/8]] | | [[10/9]], [[19/17]], [[9/8]] | ||
| Major 2nd | | Major 2nd | ||
| M2 | | M2 | ||
Line 74: | Line 69: | ||
| 7 | | 7 | ||
| 221.0526 | | 221.0526 | ||
|[[17/15]] | | [[17/15]] | ||
| Upmajor 2nd | | Upmajor 2nd | ||
| ^M2 | | ^M2 | ||
Line 81: | Line 76: | ||
| 8 | | 8 | ||
| 252.6316 | | 252.6316 | ||
|[[8/7]], [[15/13]], [[22/19]], [[7/6]] | | [[8/7]], [[15/13]], [[22/19]], [[7/6]] | ||
| Aug 2nd, Dim 3rd | | Aug 2nd, Dim 3rd | ||
| A2, d3 | | A2, d3 | ||
Line 88: | Line 83: | ||
| 9 | | 9 | ||
| 284.2105 | | 284.2105 | ||
|[[20/17]], [[13/11]], [[19/16]] | | [[20/17]], [[13/11]], [[19/16]] | ||
| Downminor 3rd | | Downminor 3rd | ||
| vm3 | | vm3 | ||
Line 95: | Line 90: | ||
| 10 | | 10 | ||
| 315.7895 | | 315.7895 | ||
|[[6/5]] | | [[6/5]] | ||
| Minor 3rd | | Minor 3rd | ||
| m3 | | m3 | ||
Line 102: | Line 97: | ||
| 11 | | 11 | ||
| 347.3684 | | 347.3684 | ||
|[[17/14]], [[11/9]] | | [[17/14]], [[11/9]] | ||
| Mid 3rd | | Mid 3rd | ||
| ~3 | | ~3 | ||
Line 109: | Line 104: | ||
| 12 | | 12 | ||
| 378.9474 | | 378.9474 | ||
|[[16/13]], [[5/4]] | | [[16/13]], [[5/4]] | ||
| Major 3rd | | Major 3rd | ||
| M3 | | M3 | ||
Line 116: | Line 111: | ||
| 13 | | 13 | ||
| 410.5263 | | 410.5263 | ||
|[[24/19]], [[19/15]], [[14/11]] | | [[24/19]], [[19/15]], [[14/11]] | ||
| Upmajor 3rd, Downdim 4th | | Upmajor 3rd, Downdim 4th | ||
| ^M3, vd4 | | ^M3, vd4 | ||
Line 123: | Line 118: | ||
| 14 | | 14 | ||
| 442.1053 | | 442.1053 | ||
|[[9/7]], [[22/17]], [[13/10]] | | [[9/7]], [[22/17]], [[13/10]] | ||
| Aug 3rd, dim 4th | | Aug 3rd, dim 4th | ||
| A3, d4 | | A3, d4 | ||
Line 130: | Line 125: | ||
| 15 | | 15 | ||
| 473.6843 | | 473.6843 | ||
|[[17/13]] | | [[17/13]] | ||
| Down 4th | | Down 4th | ||
| v4 | | v4 | ||
Line 137: | Line 132: | ||
| 16 | | 16 | ||
| 505.2632 | | 505.2632 | ||
|[[4/3]] | | [[4/3]] | ||
| Perfect 4th | | Perfect 4th | ||
| P4 | | P4 | ||
Line 144: | Line 139: | ||
| 17 | | 17 | ||
| 536.8421 | | 536.8421 | ||
|[[19/14]], [[15/11]], [[26/19]], [[11/8]] | | [[19/14]], [[15/11]], [[26/19]], [[11/8]] | ||
| Up 4th | | Up 4th | ||
| ^4 | | ^4 | ||
Line 151: | Line 146: | ||
| 18 | | 18 | ||
| 568.4211 | | 568.4211 | ||
|[[18/13]], [[7/5]] | | [[18/13]], [[7/5]] | ||
| Aug 4th | | Aug 4th | ||
| A4 | | A4 | ||
Line 158: | Line 153: | ||
| 19 | | 19 | ||
| 600.0000 | | 600.0000 | ||
|[[24/17]], [[17/12]] | | [[24/17]], [[17/12]] | ||
| Upaug 4th, downdim 5th | | Upaug 4th, downdim 5th | ||
| ^A4, vd5 | | ^A4, vd5 | ||
Line 165: | Line 160: | ||
| 20 | | 20 | ||
| 631.5789 | | 631.5789 | ||
|[[10/7]], [[13/9]] | | [[10/7]], [[13/9]] | ||
| Dim 5th | | Dim 5th | ||
| d5 | | d5 | ||
Line 172: | Line 167: | ||
| 21 | | 21 | ||
| 663.1579 | | 663.1579 | ||
|[[16/11]], [[19/13]], [[22/15]], [[28/19]] | | [[16/11]], [[19/13]], [[22/15]], [[28/19]] | ||
| Down 5th | | Down 5th | ||
| v5 | | v5 | ||
Line 179: | Line 174: | ||
| 22 | | 22 | ||
| 694.7368 | | 694.7368 | ||
|[[3/2]] | | [[3/2]] | ||
| Perfect 5th | | Perfect 5th | ||
| P5 | | P5 | ||
Line 186: | Line 181: | ||
| 23 | | 23 | ||
| 726.3157 | | 726.3157 | ||
|[[26/17]] | | [[26/17]] | ||
| Up 5th | | Up 5th | ||
| ^5 | | ^5 | ||
Line 193: | Line 188: | ||
| 24 | | 24 | ||
| 757.8947 | | 757.8947 | ||
|[[20/13]], [[17/11]], [[14/9]] | | [[20/13]], [[17/11]], [[14/9]] | ||
| Aug 5th, dim 6th | | Aug 5th, dim 6th | ||
| A5, d6 | | A5, d6 | ||
Line 200: | Line 195: | ||
| 25 | | 25 | ||
| 789.4737 | | 789.4737 | ||
|[[11/7]], [[30/19]], [[19/12]] | | [[11/7]], [[30/19]], [[19/12]] | ||
| Upaug 5th, downminor 6th | | Upaug 5th, downminor 6th | ||
| ^A5, vm6 | | ^A5, vm6 | ||
Line 207: | Line 202: | ||
| 26 | | 26 | ||
| 821.0526 | | 821.0526 | ||
|[[8/5]], [[13/8]] | | [[8/5]], [[13/8]] | ||
| Minor 6th | | Minor 6th | ||
| m6 | | m6 | ||
Line 214: | Line 209: | ||
| 27 | | 27 | ||
| 852.6316 | | 852.6316 | ||
|[[18/11]], [[28/17]] | | [[18/11]], [[28/17]] | ||
| Mid 6th | | Mid 6th | ||
| ~6 | | ~6 | ||
Line 221: | Line 216: | ||
| 28 | | 28 | ||
| 884.2105 | | 884.2105 | ||
|[[5/3]] | | [[5/3]] | ||
| Major 6th | | Major 6th | ||
| M6 | | M6 | ||
Line 228: | Line 223: | ||
| 29 | | 29 | ||
| 915.7895 | | 915.7895 | ||
|[[32/19]], [[22/13]], [[17/10]] | | [[32/19]], [[22/13]], [[17/10]] | ||
| Upmajor 6th | | Upmajor 6th | ||
| ^M6 | | ^M6 | ||
Line 235: | Line 230: | ||
| 30 | | 30 | ||
| 947.3684 | | 947.3684 | ||
|[[12/7]], [[19/11]], [[26/15]], [[7/4]] | | [[12/7]], [[19/11]], [[26/15]], [[7/4]] | ||
| Aug 6th, dim 7th | | Aug 6th, dim 7th | ||
| A6, d7 | | A6, d7 | ||
Line 242: | Line 237: | ||
| 31 | | 31 | ||
| 978.9474 | | 978.9474 | ||
|[[30/17]] | | [[30/17]] | ||
| Downminor 7th | | Downminor 7th | ||
| vm7 | | vm7 | ||
Line 249: | Line 244: | ||
| 32 | | 32 | ||
| 1010.5263 | | 1010.5263 | ||
|[[16/9]], [[34/19]], [[9/5]] | | [[16/9]], [[34/19]], [[9/5]] | ||
| Minor 7th | | Minor 7th | ||
| m7 | | m7 | ||
Line 256: | Line 251: | ||
| 33 | | 33 | ||
| 1042.1053 | | 1042.1053 | ||
|[[20/11]], [[11/6]] | | [[20/11]], [[11/6]] | ||
| Mid 7th | | Mid 7th | ||
| ~7 | | ~7 | ||
Line 263: | Line 258: | ||
| 34 | | 34 | ||
| 1073.6843 | | 1073.6843 | ||
|[[24/13]], [[13/7]], [[28/15]], [[15/8]] | | [[24/13]], [[13/7]], [[28/15]], [[15/8]] | ||
| Major 7th | | Major 7th | ||
| M7 | | M7 | ||
Line 270: | Line 265: | ||
| 35 | | 35 | ||
| 1105.2632 | | 1105.2632 | ||
|[[32/17]], [[17/9]], [[36/19]], [[19/10]] | | [[32/17]], [[17/9]], [[36/19]], [[19/10]] | ||
| Upmajor 7th, Downdim 8ve | | Upmajor 7th, Downdim 8ve | ||
| ^M7, vd8 | | ^M7, vd8 | ||
Line 277: | Line 272: | ||
| 36 | | 36 | ||
| 1136.8421 | | 1136.8421 | ||
| Aug 7th, dim 8ve | | Aug 7th, dim 8ve | ||
| A7, d8 | | A7, d8 | ||
Line 284: | Line 278: | ||
| 37 | | 37 | ||
| 1168.4211 | | 1168.4211 | ||
| Down 8ve | | Down 8ve | ||
| v8 | | v8 | ||
Line 291: | Line 284: | ||
| 38 | | 38 | ||
| 1200.0000 | | 1200.0000 | ||
| Perfect 8ve | | Perfect 8ve | ||
| P8 | | P8 | ||
| D | | D | ||
|} | |} | ||
<nowiki>* | <nowiki />* Ups and downs may be substituted with semi-sharps and semi-flats, respectively. | ||
== Instruments == | == Instruments == | ||
*[[Lumatone mapping for 38edo]] | * [[Lumatone mapping for 38edo]] | ||
*[[Skip fretting system 38 2 11]] | * [[Skip fretting system 38 2 11]] | ||
== 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]] | * [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]] | ||
[[Category:38edo| ]] <!-- | [[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]] | [[Category:Todo:add rank 2 temperaments table]] |
Revision as of 09:58, 27 October 2024
← 37edo | 38edo | 39edo → |
Theory
Since 38 = 2*19, it can be thought of as two parallel 19edos. While the halving of the step size lowers consistency and leaves it only mediocre in terms of overall relative error, the fact that the 3rd & 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. This gives several interesting possibilities for unusual near-just chords such as 15:18:22:25:30. 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 11-limit, we can add 121/120 and 176/175.
In 38df, 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 consistent within the 38df val ⟨38 60 88 106 131 140 155 161].
The harmonic series from 1 to 20 is approximated within 38df by the 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]
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 | 19-odd-limit ratios, treated as 38df |
Ups and Downs Notation* | ||
---|---|---|---|---|---|
0 | 0.0000 | Perfect 1sn | P1 | D | |
1 | 31.5789 | Up 1sn | ^1 | ^D | |
2 | 63.1579 | Aug 1sn, dim 2nd | A1, d2 | D# | |
3 | 94.7368 | 20/19, 19/18, 18/17, 17/16 | Upaug 1sn, downminor 2nd | ^A1, vm2 | ^D#, vEb |
4 | 126.3157 | 16/15, 15/14, 14/13, 13/12 | Minor 2nd | m2 | Eb |
5 | 157.8947 | 12/11, 11/10 | Mid 2nd | ~2 | vE |
6 | 189.4737 | 10/9, 19/17, 9/8 | Major 2nd | M2 | E |
7 | 221.0526 | 17/15 | Upmajor 2nd | ^M2 | ^E |
8 | 252.6316 | 8/7, 15/13, 22/19, 7/6 | Aug 2nd, Dim 3rd | A2, d3 | E#, Fb |
9 | 284.2105 | 20/17, 13/11, 19/16 | Downminor 3rd | vm3 | vF |
10 | 315.7895 | 6/5 | Minor 3rd | m3 | F |
11 | 347.3684 | 17/14, 11/9 | Mid 3rd | ~3 | ^F |
12 | 378.9474 | 16/13, 5/4 | Major 3rd | M3 | F# |
13 | 410.5263 | 24/19, 19/15, 14/11 | Upmajor 3rd, Downdim 4th | ^M3, vd4 | ^F#, vGb |
14 | 442.1053 | 9/7, 22/17, 13/10 | Aug 3rd, dim 4th | A3, d4 | Gb |
15 | 473.6843 | 17/13 | Down 4th | v4 | vG |
16 | 505.2632 | 4/3 | Perfect 4th | P4 | G |
17 | 536.8421 | 19/14, 15/11, 26/19, 11/8 | Up 4th | ^4 | ^G |
18 | 568.4211 | 18/13, 7/5 | Aug 4th | A4 | G# |
19 | 600.0000 | 24/17, 17/12 | Upaug 4th, downdim 5th | ^A4, vd5 | ^G#, vAb |
20 | 631.5789 | 10/7, 13/9 | Dim 5th | d5 | Ab |
21 | 663.1579 | 16/11, 19/13, 22/15, 28/19 | Down 5th | v5 | vA |
22 | 694.7368 | 3/2 | Perfect 5th | P5 | A |
23 | 726.3157 | 26/17 | Up 5th | ^5 | ^A |
24 | 757.8947 | 20/13, 17/11, 14/9 | Aug 5th, dim 6th | A5, d6 | A# |
25 | 789.4737 | 11/7, 30/19, 19/12 | Upaug 5th, downminor 6th | ^A5, vm6 | ^A#, vBb |
26 | 821.0526 | 8/5, 13/8 | Minor 6th | m6 | Bb |
27 | 852.6316 | 18/11, 28/17 | Mid 6th | ~6 | vB |
28 | 884.2105 | 5/3 | Major 6th | M6 | B |
29 | 915.7895 | 32/19, 22/13, 17/10 | Upmajor 6th | ^M6 | ^B |
30 | 947.3684 | 12/7, 19/11, 26/15, 7/4 | Aug 6th, dim 7th | A6, d7 | B#, Cb |
31 | 978.9474 | 30/17 | Downminor 7th | vm7 | vC |
32 | 1010.5263 | 16/9, 34/19, 9/5 | Minor 7th | m7 | C |
33 | 1042.1053 | 20/11, 11/6 | Mid 7th | ~7 | ^C |
34 | 1073.6843 | 24/13, 13/7, 28/15, 15/8 | Major 7th | M7 | C# |
35 | 1105.2632 | 32/17, 17/9, 36/19, 19/10 | Upmajor 7th, Downdim 8ve | ^M7, vd8 | ^C#, vDb |
36 | 1136.8421 | Aug 7th, dim 8ve | A7, d8 | Db | |
37 | 1168.4211 | Down 8ve | v8 | vD | |
38 | 1200.0000 | Perfect 8ve | P8 | D |
* Ups and downs may be substituted with semi-sharps and semi-flats, respectively.