27edo

From XenReference

27edo, or 27 equal divisions of the octave, is the equal tuning with a step size of (1200/27) ≈ 44.4¢, 27 of which stack to the perfect octave 2/1. It is best known as a Superpyth tuning alongside 22edo with a distinct sharp tendency in the 7-limit, and approximating prime 13 well instead of 11.

Theory

Approximation of prime harmonics in 27edo
Harmonic 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53
Error Absolute (¢) 0.0 +9.2 +13.7 +9.0 -18.0 +3.9 -16.1 +13.6 -6.1 -7.4 +10.5 +15.3 +15.4 +21.8 +1.2 +15.4
Relative (%) 0.0 +20.6 +30.8 +20.1 -40.5 +8.8 -36.1 +30.6 -13.6 -16.5 +23.7 +34.5 +34.6 +49.1 +2.6 +34.6
Steps
(reduced)
27
(0)
43
(16)
63
(9)
76
(22)
93
(12)
100
(19)
110
(2)
115
(7)
122
(14)
131
(23)
134
(26)
141
(6)
145
(10)
147
(12)
150
(15)
155
(20)

Useful aberrismic scales in 27edo include blackdye, pinedye, and their mutual superset trackdye.

Ground's tertian chord table

This table uses ground's interval name shorthand. It shows the bounding fifth on the vertical axis and the step difference between the two stacked thirds on the horizontal axis, with the center being no difference.

Fifth
19\27 8:10:13
a (1inv)
18\27 (tj
1
inv)
(j 1inv) classic
a
10:13:16
(17:22:27)

a (2inv)
(m 2inv) (tm
2
inv)
17\27 (sj 1inv) sensic
simic
13:16:20
a
sensic
taphric
(um 2inv)
16\27 6:7:9
um
10:12:15
m
18:22:27
n
4:5:6
j
14:18:21
sj
15\27 15:17:22
tim
13:>15:19
tm
15:18:22
dm
13:16:19
dj
15:19:22
tj
13:<17:19
tlj
14\27 7:8:10 19:22:27
d
classic
d
7:9
:10
13\27 18:20:25 15:17:21 18:21:25
d
5:6:7
d
18:22:25 15:19:21

Multiples

54edo

Approximation of prime harmonics in 54edo
Harmonic 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53
Error Absolute (¢) 0.0 +9.2 -8.5 +9.0 +4.2 +3.9 +6.2 -8.6 -6.1 -7.4 +10.5 -6.9 -6.8 -0.4 +1.2 -6.8
Relative (%) 0.0 +41.2 -38.4 +40.3 +19.1 +17.6 +27.7 -38.8 -27.2 -33.1 +47.3 -31.0 -30.8 -1.8 +5.2 -30.8
Steps
(reduced)
54
(0)
86
(32)
125
(17)
152
(44)
187
(25)
200
(38)
221
(5)
229
(13)
244
(28)
262
(46)
268
(52)
281
(11)
289
(19)
293
(23)
300
(30)
309
(39)

81edo

Approximation of prime harmonics in 81edo
Harmonic 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53
Error Absolute (¢) 0.0 -5.7 -1.1 -5.9 -3.2 +3.9 -1.3 -1.2 -6.1 -7.4 -4.3 +0.5 +0.6 +7.0 +1.2 +0.6
Relative (%) 0.0 -38.2 -7.6 -39.6 -21.4 +26.4 -8.4 -8.2 -40.9 -49.6 -29.0 +3.4 +3.8 +47.3 +7.8 +3.8
Steps
(reduced)
81
(0)
128
(47)
188
(26)
227
(65)
280
(37)
300
(57)
331
(7)
344
(20)
366
(42)
393
(69)
401
(77)
422
(17)
434
(29)
440
(35)
450
(45)
464
(59)