72edt
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72 equal divisions of the tritave, perfect twelfth, or 3rd harmonic (abbreviated 72edt or 72ed3), is a nonoctave tuning system that divides the interval of 3/1 into 72 equal parts of about 26.4 ¢ each. Each step represents a frequency ratio of 31/72, or the 72nd root of 3.
Intervals
| Steps | Cents | Hekts | Approximate ratios |
|---|---|---|---|
| 0 | 0 | 0 | 1/1 |
| 1 | 26.4 | 18.1 | |
| 2 | 52.8 | 36.1 | 34/33, 35/34 |
| 3 | 79.2 | 54.2 | 23/22 |
| 4 | 105.7 | 72.2 | 33/31 |
| 5 | 132.1 | 90.3 | |
| 6 | 158.5 | 108.3 | 34/31 |
| 7 | 184.9 | 126.4 | |
| 8 | 211.3 | 144.4 | 26/23, 35/31 |
| 9 | 237.7 | 162.5 | 31/27 |
| 10 | 264.2 | 180.6 | |
| 11 | 290.6 | 198.6 | 13/11 |
| 12 | 317 | 216.7 | 6/5 |
| 13 | 343.4 | 234.7 | 28/23 |
| 14 | 369.8 | 252.8 | |
| 15 | 396.2 | 270.8 | 34/27 |
| 16 | 422.7 | 288.9 | 23/18, 37/29 |
| 17 | 449.1 | 306.9 | 35/27 |
| 18 | 475.5 | 325 | |
| 19 | 501.9 | 343.1 | |
| 20 | 528.3 | 361.1 | 19/14 |
| 21 | 554.7 | 379.2 | |
| 22 | 581.2 | 397.2 | |
| 23 | 607.6 | 415.3 | 27/19 |
| 24 | 634 | 433.3 | 13/9, 36/25 |
| 25 | 660.4 | 451.4 | 19/13, 22/15 |
| 26 | 686.8 | 469.4 | |
| 27 | 713.2 | 487.5 | |
| 28 | 739.6 | 505.6 | 23/15 |
| 29 | 766.1 | 523.6 | 14/9 |
| 30 | 792.5 | 541.7 | |
| 31 | 818.9 | 559.7 | |
| 32 | 845.3 | 577.8 | 31/19 |
| 33 | 871.7 | 595.8 | 38/23 |
| 34 | 898.1 | 613.9 | |
| 35 | 924.6 | 631.9 | 29/17 |
| 36 | 951 | 650 | 26/15 |
| 37 | 977.4 | 668.1 | 37/21 |
| 38 | 1003.8 | 686.1 | 34/19 |
| 39 | 1030.2 | 704.2 | |
| 40 | 1056.6 | 722.2 | 35/19 |
| 41 | 1083.1 | 740.3 | 28/15 |
| 42 | 1109.5 | 758.3 | |
| 43 | 1135.9 | 776.4 | 27/14 |
| 44 | 1162.3 | 794.4 | |
| 45 | 1188.7 | 812.5 | |
| 46 | 1215.1 | 830.6 | |
| 47 | 1241.6 | 848.6 | |
| 48 | 1268 | 866.7 | 25/12, 27/13 |
| 49 | 1294.4 | 884.7 | 19/9 |
| 50 | 1320.8 | 902.8 | |
| 51 | 1347.2 | 920.8 | 37/17 |
| 52 | 1373.6 | 938.9 | 31/14 |
| 53 | 1400.1 | 956.9 | |
| 54 | 1426.5 | 975 | |
| 55 | 1452.9 | 993.1 | |
| 56 | 1479.3 | 1011.1 | |
| 57 | 1505.7 | 1029.2 | 31/13 |
| 58 | 1532.1 | 1047.2 | |
| 59 | 1558.5 | 1065.3 | |
| 60 | 1585 | 1083.3 | 5/2 |
| 61 | 1611.4 | 1101.4 | 33/13, 38/15 |
| 62 | 1637.8 | 1119.4 | |
| 63 | 1664.2 | 1137.5 | 34/13 |
| 64 | 1690.6 | 1155.6 | |
| 65 | 1717 | 1173.6 | 35/13 |
| 66 | 1743.5 | 1191.7 | |
| 67 | 1769.9 | 1209.7 | |
| 68 | 1796.3 | 1227.8 | 31/11 |
| 69 | 1822.7 | 1245.8 | |
| 70 | 1849.1 | 1263.9 | |
| 71 | 1875.5 | 1281.9 | |
| 72 | 1902 | 1300 | 3/1 |
Harmonics
| Harmonic | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Error | Absolute (¢) | -11.3 | +0.0 | +3.9 | -12.6 | -11.3 | +12.4 | -7.4 | +0.0 | +2.5 | -4.0 | +3.9 |
| Relative (%) | -42.7 | +0.0 | +14.6 | -47.8 | -42.7 | +47.0 | -28.1 | +0.0 | +9.5 | -15.1 | +14.6 | |
| Steps (reduced) |
45 (45) |
72 (0) |
91 (19) |
105 (33) |
117 (45) |
128 (56) |
136 (64) |
144 (0) |
151 (7) |
157 (13) |
163 (19) | |
| Harmonic | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Error | Absolute (¢) | -2.6 | +1.1 | -12.6 | +7.7 | +8.4 | -11.3 | +0.8 | -8.8 | +12.4 | +11.1 | -13.0 |
| Relative (%) | -10.0 | +4.4 | -47.8 | +29.2 | +31.9 | -42.7 | +3.0 | -33.2 | +47.0 | +42.2 | -49.2 | |
| Steps (reduced) |
168 (24) |
173 (29) |
177 (33) |
182 (38) |
186 (42) |
189 (45) |
193 (49) |
196 (52) |
200 (56) |
203 (59) |
205 (61) | |