87ed4

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← 85ed487ed489ed4 →
Prime factorization 3 × 29
Step size 27.5862¢ 
Octave 44\87ed4 (1213.79¢)
Twelfth 69\87ed4 (1903.45¢) (→23\29ed4)
Consistency limit 1
Distinct consistency limit 1

87 equal divisions of the 4th harmonic (abbreviated 87ed4) is a nonoctave tuning system that divides the interval of 4/1 into 87 equal parts of about 27.6 ¢ each. Each step represents a frequency ratio of 41/87, or the 87th root of 4.

Intervals

Steps Cents Approximate Ratios
0 0 1/1
1 27.586
2 55.172 31/30
3 82.759 22/21
4 110.345
5 137.931
6 165.517
7 193.103 19/17
8 220.69 25/22
9 248.276 15/13
10 275.862 27/23, 41/35
11 303.448 25/21, 31/26, 37/31
12 331.034 23/19
13 358.621
14 386.207
15 413.793
16 441.379
17 468.966
18 496.552
19 524.138 23/17
20 551.724
21 579.31
22 606.897 27/19
23 634.483 13/9
24 662.069 22/15
25 689.655
26 717.241
27 744.828
28 772.414 39/25
29 800 27/17
30 827.586 21/13
31 855.172 41/25
32 882.759 5/3
33 910.345 22/13
34 937.931
35 965.517
36 993.103 39/22
37 1020.69
38 1048.276
39 1075.862 41/22
40 1103.448 17/9
41 1131.034 25/13
42 1158.621 41/21
43 1186.207
44 1213.793
45 1241.379
46 1268.966
47 1296.552
48 1324.138
49 1351.724
50 1379.31
51 1406.897
52 1434.483
53 1462.069
54 1489.655
55 1517.241
56 1544.828 22/9
57 1572.414
58 1600
59 1627.586
60 1655.172 13/5
61 1682.759 37/14
62 1710.345
63 1737.931 41/15
64 1765.517
65 1793.103
66 1820.69
67 1848.276
68 1875.862
69 1903.448 3/1
70 1931.034
71 1958.621 31/10
72 1986.207 41/13
73 2013.793
74 2041.379
75 2068.966
76 2096.552
77 2124.138
78 2151.724
79 2179.31
80 2206.897
81 2234.483
82 2262.069
83 2289.655
84 2317.241
85 2344.828
86 2372.414
87 2400

Harmonics

Approximation of harmonics in 87ed4
Harmonic 2 3 4 5 6 7 8 9 10 11 12
Error Absolute (¢) +13.8 +1.5 +0.0 -0.1 -12.3 -3.3 +13.8 +3.0 +13.7 -13.4 +1.5
Relative (%) +50.0 +5.4 +0.0 -0.4 -44.6 -12.0 +50.0 +10.8 +49.6 -48.5 +5.4
Steps
(reduced)
44
(44)
69
(69)
87
(0)
101
(14)
112
(25)
122
(35)
131
(44)
138
(51)
145
(58)
150
(63)
156
(69)
Approximation of harmonics in 87ed4
Harmonic 13 14 15 16 17 18 19 20 21 22 23
Error Absolute (¢) +0.9 +10.5 +1.4 +0.0 +5.4 -10.8 +5.9 -0.1 -1.8 +0.4 +6.2
Relative (%) +3.1 +38.0 +5.0 +0.0 +19.5 -39.2 +21.5 -0.4 -6.6 +1.5 +22.5
Steps
(reduced)
161
(74)
166
(79)
170
(83)
174
(0)
178
(4)
181
(7)
185
(11)
188
(14)
191
(17)
194
(20)
197
(23)