69edo: Difference between revisions

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69edo approximation list is about 1/4-1/3 complete. I'm just saving to make sure I don't lose any progress.
Saving my progress on 69edo's list of approximate intervals. I'm around 1/3-1/2 done. I'm going to save now so I don't lose any progress and hopefully finish this chart sometime today.
Line 265: Line 265:
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|730.435
|730.435
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|32/21, 29/19
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|1.216, -1.630
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|43
|43
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|747.826
|747.826
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|17/11
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| -5.811
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|44
|44
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|765.217
|765.217
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|14/9
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|0.301
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|45
|45
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|782.609
|782.609
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|11/7
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|0.117
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|46
|46
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|800.000
|800.000
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|27/17
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|817.391
|817.391
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|8/5
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|3.705
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|48
|48
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|834.783
|834.783
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|34/21
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|886.957
|886.957
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|5/3
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|2.598
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|52
|52
Line 385: Line 385:
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|1078.261
|1078.261
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|28/15
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| -2.296
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|63
|63

Revision as of 11:49, 21 December 2020

The 69 equal division or 69-EDO, which divides the octave into 69 equal parts of 17.391 cents each, has been called "the love-child of 23edo and quarter-comma meantone". Nice. As a meantone system, it is on the flat side, with a fifth of 695.652 cents. Such a fifth is closer to 2/7-comma meantone than 1/4-comma, and is nearly identical to that of "Synch-Meantone", or Wilson's equal beating meantone, wherein the perfect fifth and the major third beat at equal rates. Therefore 69edo can be treated as a closed system of Synch-Meantone for most purposes.

In the 7-limit it is a mohajira system, tempering out 6144/6125, but not a septimal meantone system, as 126/125 maps to one step. It also supports the 12&69 temperament tempering out 3125/3087 along with 81/80. In the 11-limit it tempers out 99/98, and supports the 31&69 variant of mohajira, identical to the standard 11-limit mohajira in 31EDO but not in 69.

Degree Name and Abbreviation Cents Approximate Ratios* Error (abs, ¢)
0 Natural Unison, 1 0.000 1/1 0.000
1 17.391
2 34.783
3 52.174 20/19 -1.844
4 69.565
5 86.957
6 104.348 17/16 -0.608
7 121.739 15/14 2.296
8 139.130 13/12 0.558
9 156.522
10 173.913
11 191.304 19/17 -1.253
12 208.696 9/8 4.786
13 226.087 8/7 -5.087
14 243.478 23/20 1.518
15 260.870 7/6, 29/25 -6.001, 3.920
16 278.261 27/23 0.670
17 295.652 32/27 1.517
18 313.043 6/5 -2.598
19 330.435 23/19 -0.327
20 347.826 11/9 0.418
21 365.217 21/17 -0.608
22 382.609 5/4 -3.705
23 400.000
24 417.391 14/11 -0.117
25 434.783 9/7 -0.301
26 452.174 13/10 -2.040
27 469.565 21/16 -1.216
28 486.957
29 504.348 4/3 6.303
30 521.739 23/17 -1.580
31 539.130 15/11 2.180
32 556.522 11/8, 29/21 5.204, -2.275
33 573.913 7/5, 25/18 -8.600, 5.196
34 591.304 31/22 -2.413
35 608.696 10/7, 27/19 -8.792, 0.344
36 626.087 33/23 1.088
37 643.478 29/20 0.215
38 660.870 19/13, 22/15 3.884, -2.180
39 678.261 34/23, 37/25 1.580, -0.456
40 695.652 3/2 -6.303
41 713.043
42 730.435 32/21, 29/19 1.216, -1.630
43 747.826 17/11 -5.811
44 765.217 14/9 0.301
45 782.609 11/7 0.117
46 800.000 27/17
47 817.391 8/5 3.705
48 834.783 34/21
49 852.174
50 869.565
51 886.957 5/3 2.598
52 904.348
53 921.739
54 939.130
55 956.522
56 973.913
57 991.304
58 1008.696
59 1026.087
60 1043.478
61 1060.870
62 1078.261 28/15 -2.296
63 1095.652
64 1113.043
65 1130.435
66 1147.826
67 1165.217
68 1182.609
69 Octave, 8 1200.000 2/1 0.000

*some simpler ratios listed