15edt: Difference between revisions
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'''15EDT''' is the [[Edt|equal division of the third harmonic]] into 15 parts of 126.7970 [[cent|cents]] each, corresponding to 9.4639 [[edo]]. | |||
Lookalikes: [[19ed4]] | |||
=Intervals | ==Properties== | ||
15EDT has harmonics 5 and 13 closely in tune, but does not do so well for 7 and 11, which are quite sharp. It tempers out the comma |0 22 -15> in the 5-limit, which is tempered out by [[19edo]] but has an [[optimal patent val]] of [[303edo]]. As a 3.5.13 subgroup system, it tempers out 2197/2187 and 3159/3125. Using the patent val, it tempers out 375/343 and 6561/6125 in the 7-limit; 81/77, 125/121, and 363/343 in the 11-limit; 65/63, 169/165, 585/539, and 1287/1225 in the 13-limit; 51/49, 121/119, 125/119, 189/187, and 195/187 in the 17-limit (no-twos subgroup). 15EDT is related to the 2.3.5.13 subgroup temperament 19&123, which has[[category:macrotonal]] a mapping [<1 0 0 0|, <0 15 22 35|], where the generator, an approximate 27/25, has a POTE tuning of 126.773, very close to 15EDT. | |||
With the patent 4, it tempers out 36/35, 64/63, and 375/343 in the 3.4.5.7 subgroup; 45/44, 80/77, 81/77, and 363/343 in the 3.4.5.7.11 subgroup; 52/49, 65/63, 65/64, 143/140, and 169/165 in the 3.4.5.7.11.13 subgroup; 51/49, 52/51, 85/84, and 121/119 in the 3.4.5.7.11.13.17 subgroup. | |||
==Intervals== | |||
{| class="wikitable" | {| class="wikitable" | ||
| Line 15: | Line 18: | ||
| | 0 | | | 0 | ||
| | 0 | | | 0 | ||
| | <span style="color: #660000;">[[ | | | <span style="color: #660000;">[[1/1]]</span> | ||
|- | |- | ||
| | 1 | | | 1 | ||
| | 126.797 | | | 126.797 | ||
| | [[ | | | [[14/13]], [[15/14]], [[16/15]], 29/27 | ||
|- | |- | ||
| | 2 | | | 2 | ||
| | 253.594 | | | 253.594 | ||
| | [[ | | | [[15/13]] | ||
|- | |- | ||
| | 3 | | | 3 | ||
| | 380.391 | | | 380.391 | ||
| | <span style="color: #660000;">[[ | | | <span style="color: #660000;">[[5/4]]</span> | ||
|- | |- | ||
| | 4 | | | 4 | ||
| | 507.188 | | | 507.188 | ||
| | [[ | | | [[4/3]] | ||
|- | |- | ||
| | 5 | | | 5 | ||
| | 633.985 | | | 633.985 | ||
| | [[ | | | [[13/9]] | ||
|- | |- | ||
| | 6 | | | 6 | ||
| | 760.782 | | | 760.782 | ||
| | <span style="color: #660000;">[[ | | | <span style="color: #660000;">[[14/9]]</span> | ||
|- | |- | ||
| | 7 | | | 7 | ||
| | 887.579 | | | 887.579 | ||
| | [[ | | | [[5/3]] | ||
|- | |- | ||
| | 8 | | | 8 | ||
| | 1014.376 | | | 1014.376 | ||
| | [[ | | | [[9/5]] | ||
|- | |- | ||
| | 9 | | | 9 | ||
| | 1141.173 | | | 1141.173 | ||
| | <span style="color: #660000;">[[ | | | <span style="color: #660000;">[[27/14]]</span> | ||
|- | |- | ||
| | 10 | | | 10 | ||
| | 1267.970 | | | 1267.970 | ||
| | [[27/ | | | [[27/26|27/13]] | ||
|- | |- | ||
| | 11 | | | 11 | ||
| | 1394.767 | | | 1394.767 | ||
| | [[ | | | [[9/4]] ([[9/8]] plus an octave) | ||
|- | |- | ||
| | 12 | | | 12 | ||
| | 1521.564 | | | 1521.564 | ||
| | [[ | | | [[12/5]] (<span style="color: #660000;">[[6/5]]</span> plus an octave) | ||
|- | |- | ||
| | 13 | | | 13 | ||
| | 1648.361 | | | 1648.361 | ||
| | [[ | | | [[13/5]] ([[13/10]] plus an octave) | ||
|- | |- | ||
| | 14 | | | 14 | ||
| | 1775.158 | | | 1775.158 | ||
| | [[ | | | [[14/5]] ([[7/5]] plus an octave) | ||
|- | |- | ||
| | 15 | | | 15 | ||
| | 1901.955 | | | 1901.955 | ||
| | [[ | | | [[3/1]] | ||
|} | |} | ||
15edt contains 4 intervals from [[ | 15edt contains 4 intervals from [[5edt]] and 2 intervals from [[3edt]], meaning that it contains 6 redundant intervals and 8 new intervals. The new intervals introduced include good approximations to 15/14, 15/13, 4/3, 5/3 and their tritave inverses. This allows for new chord possibilities such as 1:3:4:5:9:12:13:14:15:16... | ||
15edt also contains a 5L5s MOS similar to Blackwood Decatonic, which I call Ebony. This MOS has a period of 1/5 of the tritave and the generator is a single step. The major scale is sLsLsLsLsL, and the minor scale is LsLsLsLsLs. | 15edt also contains a 5L5s MOS similar to Blackwood Decatonic, which I call Ebony. This MOS has a period of 1/5 of the tritave and the generator is a single step. The major scale is sLsLsLsLsL, and the minor scale is LsLsLsLsLs. | ||
| Line 84: | Line 87: | ||
15edt approximates the 5th and 13th harmonics (and 29th) very well. Taking these as consonances one obtains an 3L+3s MOS "augmented scale", in which three 13/9 intervals close to a tritave, and another three are set 5/3 away. | 15edt approximates the 5th and 13th harmonics (and 29th) very well. Taking these as consonances one obtains an 3L+3s MOS "augmented scale", in which three 13/9 intervals close to a tritave, and another three are set 5/3 away. | ||
=Z function= | ==Z function== | ||
Below is a plot of the [[The_Riemann_Zeta_Function_and_Tuning#Removing primes|no-twos Z function]] in the vicinity of 15edt: | Below is a plot of the [[The_Riemann_Zeta_Function_and_Tuning#Removing primes|no-twos Z function]] in the vicinity of 15edt: | ||
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[http://www.youtube.com/watch?v=bC_Pc4jKm2k http://www.youtube.com/watch?v=bC_Pc4jKm2k] | [http://www.youtube.com/watch?v=bC_Pc4jKm2k http://www.youtube.com/watch?v=bC_Pc4jKm2k] | ||
[[Category:Edt]] | |||
[[Category:Edonoi]] | |||