9edt: Difference between revisions

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The 9 equal division of 3, the tritave, divides it into 9 equal steps of size 211.328 cents each. It has a decent 7 and an excellent 13, but a 5 which is 39 cents flat; if octaves were added and it was a sixth, it would count as a neutral sixth. The corresponding 5/3 is 845 cents, which is a neutral sixth between 8/5 and 5/3, which is really more of a 13/8, though this is allegedly a no-twos tuning. On the 3.7.13 subgroup it tempers out 351/343 and 2197/2187. 9edt is the third [[The_Riemann_Zeta_Function_and_Tuning#Removing primes|no-twos zeta peak edt]].
The '''9 equal division of 3''', the [[tritave]], divides it into 9 equal steps of size 211.328 [[cent]]s each. It has a decent 7 and an excellent 13, but a 5 which is 39 cents flat; if octaves were added and it was a sixth, it would count as a [[neutral sixth]]. The corresponding interval for [[5/3]] is 845 cents, which is a neutral sixth between [[8/5]] and [[5/3]], which is really more of a [[13/8]], though this is allegedly a no-twos tuning. On the 3.7.13 [[subgroup]] it tempers out [[351/343]] and [[2197/2187]]. 9edt is the third [[The_Riemann_Zeta_Function_and_Tuning#Removing primes|no-twos zeta peak edt]].


Following [[4edt|4edt]], this is the next "Lambda" (BP related) equal division of the tritave; in a certain sense analogous to [[7edo|7edo]] in diatonic music.
Following [[4edt]], this is the next "Lambda" (BP related) equal division of the tritave; in a certain sense analogous to [[7edo]] in diatonic music.


This scale is also related to [[17edo|17edo]] by which it may be approximated by playing every third step (the 17edo non-octave whole-tone scale), the discrepancy is only about four cents when it gets to 3/1.
This scale is also related to [[17edo]] by which it may be approximated by playing every third step (the 17edo non-octave whole-tone scale), the discrepancy is only about four cents when it gets to [[3/1]].


0: 1/1
{| class="wikitable"
! Steps
! Size <br/><small>(in [[cent|&cent;]])</small>
! Comparable intervals
|-
| 0
| 0
| [[1/1]]
|-
| 1
| 211.328
| [[9/8]] (204)
|-
| 2
| 422.657
| [[9/7]] (435)
|-
| 3
| 633.985
| [[13/9]] (637)
|-
| 4
| 845.313
| [[13/8]] (841), [[5/3]] (884), [[8/5]] (814)
|-
| 5
| 1056.642
| [[9/5]] (1018), [[11/6]] (1049)
|-
| 6
| 1267.970
| [[27/13]] (1265)
|-
| 7
| 1479.298
| [[7/3]] (1467)
|-
| 8
| 1690.627
| [[8/3]] (1698)
|-
| 9
| 1901.955
| [[3/1]]
|}


1: 211.328 cents 9/8
[[Category:Macrotonal]]
 
[[Category:Edt]]
2: 422.657 cents 9/7
 
3: 633.985 cents 13/9
 
4: 845.313 cents 5/3
 
5: 1056.642 cents 9/5
 
6: 1267.970 cents 27/13
 
7: 1479.298 cents 7/3
 
8: 1690.627 cents 8/3
 
9: 3/1
[[category:macrotonal]]

Revision as of 12:36, 2 October 2018

The 9 equal division of 3, the tritave, divides it into 9 equal steps of size 211.328 cents each. It has a decent 7 and an excellent 13, but a 5 which is 39 cents flat; if octaves were added and it was a sixth, it would count as a neutral sixth. The corresponding interval for 5/3 is 845 cents, which is a neutral sixth between 8/5 and 5/3, which is really more of a 13/8, though this is allegedly a no-twos tuning. On the 3.7.13 subgroup it tempers out 351/343 and 2197/2187. 9edt is the third no-twos zeta peak edt.

Following 4edt, this is the next "Lambda" (BP related) equal division of the tritave; in a certain sense analogous to 7edo in diatonic music.

This scale is also related to 17edo by which it may be approximated by playing every third step (the 17edo non-octave whole-tone scale), the discrepancy is only about four cents when it gets to 3/1.

Steps Size
(in ¢)
Comparable intervals
0 0 1/1
1 211.328 9/8 (204)
2 422.657 9/7 (435)
3 633.985 13/9 (637)
4 845.313 13/8 (841), 5/3 (884), 8/5 (814)
5 1056.642 9/5 (1018), 11/6 (1049)
6 1267.970 27/13 (1265)
7 1479.298 7/3 (1467)
8 1690.627 8/3 (1698)
9 1901.955 3/1