21edo: Difference between revisions

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Intervals: link ratios + some small changes
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! Steps
! Steps
! Cents
! Cents
! 43-odd-limit ratios*
! Approximate atios*
! Additional ratios<br>of 17, 19, and 27**
! Additional ratios<br>of 17, 19, and 27**
!Other ratios†
!Other ratios†
Line 37: Line 37:
| 0
| 0
| 0.00
| 0.00
| colspan="3" | 1/1
| colspan="3" | [[1/1]]
|-
|-
| 1
| 1
| 57.14
| 57.14
| 29/28, 30/29, 31/30, 32/31, 33/32
| [[29/28]], [[30/29]], [[31/30]], [[32/31]], [[33/32]]
| 28/27, 34/33, 39/38
| [[28/27]], [[34/33]], [[39/38]]
|21/20
| [[21/20]]
|-
|-
| 2
| 2
| 114.29
| 114.29
| 15/14, 16/15, 31/29, 33/31, 46/43
| [[15/14]], [[16/15]], [[31/29]], [[33/31]], [[46/43]]
| 17/16, 29/27
| [[17/16]], [[29/27]]
|14/13
| [[14/13]]
|-
|-
| 3
| 3
| 171.43
| 171.43
| 11/10, 32/29, 31/28, 43/39
| [[11/10]], [[32/29]], [[31/28]], [[43/39]]
| 10/9, 19/17, 34/31
| [[10/9]], [[19/17]], [[34/31]]
|''9/8, 13/12''
| ''[[9/8]], [[13/12]]''
|-
|-
| 4
| 4
| 228.57
| 228.57
| 8/7, 33/29
| [[8/7]], [[33/29]]
| 17/15, 31/27, 38/33, 43/38
| [[17/15]], [[31/27]], [[38/33]], [[43/38]]
|
|
|-
|-
| 5
| 5
| 285.71
| 285.71
| 13/11, 33/28, 46/39
| [[13/11]], [[33/28]], [[46/39]]
| 19/16, 27/23, 32/27, 34/29
| [[19/16]], [[27/23]], [[32/27]], [[34/29]]
|''6/5,'' 7/6
|''[[6/5]],'' [[7/6]]
|-
|-
| 6
| 6
| 342.86
| 342.86
| 28/23, 39/32
| [[28/23]], [[39/32]]
| 11/9, 17/14, 23/19, 38/31
| [[11/9]], [[17/14]], [[23/19]], [[38/31]]
|16/13
| [[16/13]]
|-
|-
| 7
| 7
| 400.00
| 400.00
| 29/23, 39/31
| [[29/23]], [[39/31]]
| 19/15, 34/27, 43/34, 54/43
| [[19/15]], [[34/27]], [[43/34]], [[54/43]]
|5/4, ''9/7''
| [[5/4]], ''[[9/7]]''
|-
|-
| 8
| 8
| 457.14
| 457.14
| 13/10, 30/23, 39/30, 43/33, 56/43
| [[13/10]], [[30/23]], [[39/30]], [[43/33]], [[56/43]]
| 38/29
| [[38/29]]
|21/16
| [[21/16]]
|-
|-
| 9
| 9
| 514.29
| 514.29
| 31/23, 39/29, 43/32, 58/43
| [[31/23]], [[39/29]], [[43/32]], [[58/43]]
| 19/14, 23/17
| [[19/14]], [[23/17]]
|4/3
| [[4/3]]
|-
|-
| 10
| 10
| 571.43
| 571.43
| 32/23, 39/28, 46/33, 43/31, 60/43
| [[32/23]], [[39/28]], [[46/33]], [[43/31]], [[60/43]]
| 18/13, 38/27
| [[18/13]], [[38/27]]
|7/5
| [[7/5]]
|-
|-
| 11
| 11
| 628.57
| 628.57
| 23/16, 56/39, 33/23, 43/30, 62/43
| [[23/16]], [[56/39]], [[33/23]], [[43/30]], [[62/43]]
| 13/9, 27/19
| [[13/9]], [[27/19]]
|10/7
| [[10/7]]
|-
|-
| 12
| 12
| 685.71
| 685.71
| 46/31, 58/39, 43/29, 64/43
| [[46/31]], [[58/39]], [[43/29]], [[64/43]]
| 28/19, 34/23
| [[28/19]], [[34/23]]
|3/2
| [[3/2]]
|-
|-
| 13
| 13
| 742.86
| 742.86
| 20/13, 23/15, 60/39, 43/28, 66/43
| [[20/13]], [[23/15]], [[60/39]], [[43/28]], [[66/43]]
| 29/19
| [[29/19]]
|32/21
| [[32/21]]
|-
|-
| 14
| 14
| 800.00
| 800.00
| 46/29, 62/39
| [[46/29]], [[62/39]]
| 30/19, 27/17, 43/27, 68/43
| [[30/19]], [[27/17]], [[43/27]], [[68/43]]
|8/5, ''14/9''
| [[8/5]], ''[[14/9]]''
|-
|-
| 15
| 15
| 857.14
| 857.14
| 23/14, 64/39
| [[23/14]], [[64/39]]
| 18/11, 28/17, 38/23, 31/19
| [[18/11]], [[28/17]], [[38/23]], [[31/19]]
|13/8
| [[13/8]]
|-
|-
| 16
| 16
| 914.29
| 914.29
| 22/13, 56/33, 39/23
| [[22/13]], [[56/33]], [[39/23]]
| 32/19, 27/16, 46/27, 29/17
| [[32/19]], [[27/16]], [[46/27]], [[29/17]]
|''5/3'', 12/7
|''[[5/3]]'', [[12/7]]
|-
|-
| 17
| 17
| 971.43
| 971.43
| 7/4, 58/33
| [[7/4]], [[58/33]]
| 30/17, 54/31, 33/19, 76/43
| [[30/17]], [[54/31]], [[33/19]], [[76/43]]
|
|
|-
|-
| 18
| 18
| 1028.57
| 1028.57
| 20/11, 29/16, 56/31, 78/43
| [[20/11]], [[29/16]], [[56/31]], [[78/43]]
| 9/5, 34/19, 31/17
| [[9/5]], [[34/19]], [[31/17]]
|''16/9, 24/13''
|''[[16/9]], [[24/13]]''
|-
|-
| 19
| 19
| 1085.71
| 1085.71
| 15/8, 28/15, 58/31, 62/33, 43/23
| [[15/8]], [[28/15]], [[58/31]], [[62/33]], [[43/23]]
| 32/17, 54/29
| [[32/17]], [[54/29]]
|13/7
| [[13/7]]
|-
|-
| 20
| 20
| 1142.86
| 1142.86
| 29/15, 56/29, 31/16, 60/31, 64/33
| [[29/15]], [[56/29]], [[31/16]], [[60/31]], [[64/33]]
| 27/14, 33/17, 76/39
| [[27/14]], [[33/17]], [[76/39]]
|40/21
| [[40/21]]
|-
|-
| 21
| 21
| 1200.00
| 1200.00
| colspan="3" | 2/1
| colspan="3" | [[2/1]]
|}
|}
<nowiki/>*In the 2.15.7.33.39.23.29.31.43 subgroup
<nowiki/>*43-odd-limit ratios of the 2.15.7.33.39.23.29.31.43 subgroup


<nowiki>**</nowiki>Odd 27 by direct approximation
<nowiki/>**Odd 27 by direct approximation


†All by patent val
†All by patent val


Note: In the second column, the ratios 9/5, 11/9, 13/9, and their octave complements are all included here, being 27/15, 33/27, and 39/27 respectively. These ratios are mapped inconsistently to their second-best approximations in the patent val, so despite 9/8 and 10/9 being listed in the same row, 21edo is ''not'' a [[meantone]] system.
Note: In the second column, the ratios 9/5, 11/9, 13/9, and their octave complements are all included here, being 27/15, 33/27, and 39/27 respectively. These ratios are mapped inconsistently to their second-best approximations in the patent val, so despite 9/8 and 10/9 being listed in the same row in the table above, 21edo is ''not'' a [[meantone]] system.


== Notation ==
== Notation ==