97ed9

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Prime factorization 97 (prime)
Step size 39.2156¢ 
Octave 31\97ed9 (1215.68¢)
Twelfth 49\97ed9 (1921.56¢)
Consistency limit 2
Distinct consistency limit 2

97ed9 is an equal-step tuning system created by dividing the interval of 9/1 into 97 equal parts.

This system can be approximated as 30.6001 EDO, meaning each step of 97ed9 corresponds closely to five steps of 153edo.

97ed9 is a non-octave, non-tritave scale.

Theory

97ed9 features a well-balanced harmonic series segment from 4 to 9 and another from 39 to 50. It performs well across all prime harmonics from 5 to 19, with the exception of 13, which is slightly flat.

97ed9 sets a height record on the Riemann zeta function with primes 2 and 3 removed, approximating 30.59745 EDO. This record remains unbeaten until approximately 41.3478 EDO.

Additionally, 97ed9 is close to 125zpi (see Zeta peak index).

Harmonic series

2 to 19

Approximation of harmonics in 97ed9
Harmonic 2 3 4 5 6 7 8 9 10
Error Absolute (¢) +15.7 +19.6 -7.9 -2.0 -3.9 +3.7 +7.8 +0.0 +13.7
Relative (%) +40.0 +50.0 -20.0 -5.1 -10.0 +9.5 +20.0 +0.0 +34.9
Steps
(reduced)
31
(31)
49
(49)
61
(61)
71
(71)
79
(79)
86
(86)
92
(92)
97
(0)
102
(5)
(contd.)
Harmonic 11 12 13 14 15 16 17 18 19
Error Absolute (¢) +5.5 +11.8 -9.2 +19.4 +17.6 -15.7 -3.0 +15.7 +0.5
Relative (%) +14.1 +30.0 -23.4 +49.5 +44.9 -40.0 -7.7 +40.0 +1.3
Steps
(reduced)
106
(9)
110
(13)
113
(16)
117
(20)
120
(23)
122
(25)
125
(28)
128
(31)
130
(33)

36 to 53

Approximation of harmonics in 97ed9
Harmonic 36 37 38 39 40 41 42 43 44
Error Absolute (¢) -7.9 -16.1 +16.2 +10.4 +5.8 +2.3 -0.2 -1.7 -2.3
Relative (%) -20.0 -41.0 +41.3 +26.6 +14.9 +5.8 -0.5 -4.4 -5.9
Steps
(reduced)
158
(61)
159
(62)
161
(64)
162
(65)
163
(66)
164
(67)
165
(68)
166
(69)
167
(70)
(contd.)
Harmonic 45 46 47 48 49 50 51 52 53
Error Absolute (¢) -2.0 -0.8 +1.1 +3.9 +7.4 +11.7 +16.6 -17.0 -10.8
Relative (%) -5.1 -2.2 +2.9 +10.0 +18.9 +29.7 +42.3 -43.4 -27.5
Steps
(reduced)
168
(71)
169
(72)
170
(73)
171
(74)
172
(75)
173
(76)
174
(77)
174
(77)
175
(78)

Intervals

Steps Cents Approximate ratios
0 0 1/1
1 39.2
2 78.4 22/21
3 117.6 15/14, 31/29
4 156.9
5 196.1
6 235.3 39/34
7 274.5 34/29, 41/35
8 313.7
9 352.9 38/31
10 392.2
11 431.4
12 470.6
13 509.8
14 549
15 588.2
16 627.4
17 666.7 25/17
18 705.9
19 745.1
20 784.3 11/7
21 823.5 37/23
22 862.7
23 902
24 941.2 43/25
25 980.4
26 1019.6
27 1058.8 35/19
28 1098
29 1137.3
30 1176.5
31 1215.7
32 1254.9 31/15
33 1294.1
34 1333.3 41/19
35 1372.5
36 1411.8 43/19
37 1451
38 1490.2 26/11
39 1529.4
40 1568.6
41 1607.8 38/15, 43/17
42 1647.1
43 1686.3
44 1725.5
45 1764.7
46 1803.9
47 1843.1 29/10
48 1882.3
49 1921.6
50 1960.8 31/10
51 2000
52 2039.2
53 2078.4
54 2117.6 17/5
55 2156.9
56 2196.1
57 2235.3
58 2274.5
59 2313.7 19/5
60 2352.9
61 2392.1
62 2431.4
63 2470.6
64 2509.8
65 2549
66 2588.2
67 2627.4
68 2666.7 14/3
69 2705.9
70 2745.1 44/9
71 2784.3 5/1
72 2823.5
73 2862.7
74 2902
75 2941.2
76 2980.4
77 3019.6
78 3058.8 41/7
79 3098
80 3137.2
81 3176.5
82 3215.7
83 3254.9
84 3294.1
85 3333.3
86 3372.5
87 3411.8
88 3451 22/3
89 3490.2 15/2
90 3529.4
91 3568.6
92 3607.8
93 3647
94 3686.3
95 3725.5 43/5
96 3764.7
97 3803.9