38ed7/3: Difference between revisions

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{{ED intro}}
{{ED intro}}


While 38ed7/3 fails to accurately represent low primes, it provides great approximations of the 13th, 17th, 19th, and a multitude of higher prime harmonics, and also handles the interval of [[5/3]] well. But 38ed7/3 should, most of all, be noted for the exceptional quality of its approximation to [[11/9]], which is a mere 0.0088 cents off from just. Its natural subgroup in the [[19-limit]] is 7/3.5/3.11/9.13.17.19, but this can extend to include higher primes, especially 29, 31, and 37.
== Theory ==
While 38ed7/3 fails to accurately represent low [[prime interval|prime harmonics]], it provides great approximations of the [[13/1|13th]], [[17/1|17th]], [[19/1|19th]], and a multitude of higher primes, and also handles the interval of [[5/3]] well. But 38ed7/3 should, most of all, be noted for the exceptional quality of its approximation to [[11/9]], which is a mere 0.0088 cents off from just. Its natural subgroup in the [[19-limit]] is 5/3.7/3.11/9.13.17.19, but this can extend to include higher primes, especially [[29/1|29]], [[31/1|31]], and [[37/1|37]].


38ed7/3 possesses a shimmering octave at 31 steps in, therefore making this a potential octave-compressed version of [[31edo]], one that sacrifices its notable accuracy in the [[7-limit]] (though a number of 7-limit intervals are still portrayed passably due to the common flat tendency of harmonics 2, 3, 5, and 7) in favor of a huge number of high primes.
38ed7/3 possesses a shimmering octave at 31 steps in, therefore making this a potential octave-compressed version of [[31edo]], one that sacrifices its notable accuracy in the [[7-limit]] (though a number of 7-limit intervals are still portrayed passably due to the common flat tendency of harmonics 2, 3, 5, and 7) in favor of a huge number of high primes.
=== Harmonics ===
{{Harmonics in equal|38|7|3|columns=11}}
{{Harmonics in equal|38|7|3|columns=12|start=12|collapsed=1|title=Approximation of harmonics in 38ed7/3 (continued)}}


== Intervals ==
== Intervals ==
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|1466.8709
|1466.8709
|}
|}
== Harmonics ==
{{Harmonics in equal
| steps = 38
| num = 7
| denom = 3
| intervals = prime
}}
{{Harmonics in equal
| steps = 38
| num = 7
| denom = 3
| start = 12
| collapsed = 1
| intervals = prime
}}

Revision as of 18:17, 14 May 2026

← 37ed7/3 38ed7/3 39ed7/3 →
Prime factorization 2 × 19
Step size 38.6019 ¢ 
Octave 31\38ed7/3 (1196.66 ¢)
(semiconvergent)
Twelfth 49\38ed7/3 (1891.49 ¢)
Consistency limit 8
Distinct consistency limit 8

38 equal divisions of 7/3 (abbreviated 38ed7/3) is a nonoctave tuning system that divides the interval of 7/3 into 38 equal parts of about 38.6 ¢ each. Each step represents a frequency ratio of (7/3)1/38, or the 38th root of 7/3.

Theory

While 38ed7/3 fails to accurately represent low prime harmonics, it provides great approximations of the 13th, 17th, 19th, and a multitude of higher primes, and also handles the interval of 5/3 well. But 38ed7/3 should, most of all, be noted for the exceptional quality of its approximation to 11/9, which is a mere 0.0088 cents off from just. Its natural subgroup in the 19-limit is 5/3.7/3.11/9.13.17.19, but this can extend to include higher primes, especially 29, 31, and 37.

38ed7/3 possesses a shimmering octave at 31 steps in, therefore making this a potential octave-compressed version of 31edo, one that sacrifices its notable accuracy in the 7-limit (though a number of 7-limit intervals are still portrayed passably due to the common flat tendency of harmonics 2, 3, 5, and 7) in favor of a huge number of high primes.

Harmonics

Approximation of harmonics in 38ed7/3
Harmonic 2 3 4 5 6 7 8 9 10 11 12
Error Absolute (¢) -3.3 -10.5 -6.7 -7.0 -13.8 -10.5 -10.0 +17.7 -10.3 +17.7 -17.1
Relative (%) -8.7 -27.1 -17.3 -18.1 -35.8 -27.1 -26.0 +45.8 -26.7 +45.8 -44.4
Steps
(reduced)
31
(31)
49
(11)
62
(24)
72
(34)
80
(4)
87
(11)
93
(17)
99
(23)
103
(27)
108
(32)
111
(35)
Approximation of harmonics in 38ed7/3 (continued)
Harmonic 13 14 15 16 17 18 19 20 21 22 23 24
Error Absolute (¢) -1.3 -13.8 -17.4 -13.4 -2.5 +14.3 -2.1 -13.7 +17.7 +14.3 +14.6 +18.1
Relative (%) -3.4 -35.8 -45.2 -34.6 -6.5 +37.1 -5.4 -35.4 +45.8 +37.2 +37.8 +46.9
Steps
(reduced)
115
(1)
118
(4)
121
(7)
124
(10)
127
(13)
130
(16)
132
(18)
134
(20)
137
(23)
139
(25)
141
(27)
143
(29)

Intervals

Degrees Enneatonic ed11\9~ed7/3
1 G^ 38.5965 38.6019
Jbv Abv
2 Jb Ab 77.193 77.2037
3 Jb^ Ab^ 115.7895 115.8056
G#v
4 G# 154.386 154.4075
5 G#^ 192.98245 193.0093
Jv Av
6 J A 231.57895 231.6112
7 J^/Av A^/Bv 270.1754 270.2131
8 A B 308.7719 308.8149
9 A^/Bbv B^/Cbv 347.3684 347.4168
10 Bb Cb 385.9649 386.0187
11 Bb^/A#v Cb^/B#v 424.5614 424.6205
12 A# B# 463.1579 463.2224
13 A#^/Bv B#^/Cv 501.7544 502.6667
14 B C 540.3509 540.4261
15 B^/Cv C^/Qv 578.9474 579.028
16 C Q 617.5439 617.6299
17 C^/Qbv Q^/Dbv 656.14035 656.2317
18 Qb Db 694.7368 694.8336
19 Qb^/C#v Db^/Q#v 733.3 733.43545
20 C# Q# 771.9298 772.0373
21 C#^/Qv Q#/Dv 810.5263 810.6392
22 Q D 849.1228 849.24105
23 Q^/Dv D^/Sv 887.7193 887.8429
24 D S 926.3158 926.4448
25 D^ S^ 964.9123 965.04665
Ebv
26 Eb 1003.5088 1003.6485
27 Eb^ 1042.1053 1042.2504
D#v S#v
28 D# S# 1080.70175 1080.85225
29 D#^ S#^ 1119.29825 1119.4541
Ev
30 E 1157.8947 1158.0559
31 E^/Fbv 1196.4912 1196.6578
32 Fb 1235.0877 1235.2567
33 Fb^/E#v 1273.68425 1273.8616
34 E# 1312.2807 1312.4634
35 E#^/Fv 1350.8772 1351.0654
36 F 1389.4737 1389.6672
37 F^/Gv 1428.0702 1428.269
38 G 1466.6 1466.8709