23edo: Difference between revisions
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However, one can also map 3/2 to 14 degrees of 23-EDO without significantly increasing the error, taking us to a [[7-limit]] temperament where two 'broad 3/2's equals 7/3, meaning 28/27 is tempered out, and six 4/3's octave-reduced equals 5/4, meaning 4096/3645 is tempered out. Both of these are very large commas, so this is not at all an accurate temperament, but it is related to [[13edo|13-EDO]] and [[18edo|18-EDO]] and produces [[MOSScales|MOS scales]] of 5 and 8 notes: 5 5 4 5 4 (the [[3L 2s|"anti-pentatonic"]]) and 4 1 4 1 4 4 1 4 (the "quarter-tone" version of the Blackwood/[http://en.wikipedia.org/wiki/Paul_Rapoport_%28music_critic%29 Rapoport]/Wilson 13-EDO "subminor" scale). Alternatively we can treat this temperament as a 2.9.21 subgroup, and instead of calling 9 degrees of 23-EDO a Sub-"4/3", we can call it 21/16. Here three 21/16's gets us to 9/4, meaning 1029/1024 is tempered out. This allows us to treat a triad of 0-4-9 degrees of 23-EDO as an approximation to 16:18:21, and 0-5-9 as 1/(16:18:21); both of these triads are abundant in the 8-note MOS scale. | However, one can also map 3/2 to 14 degrees of 23-EDO without significantly increasing the error, taking us to a [[7-limit]] temperament where two 'broad 3/2's equals 7/3, meaning 28/27 is tempered out, and six 4/3's octave-reduced equals 5/4, meaning 4096/3645 is tempered out. Both of these are very large commas, so this is not at all an accurate temperament, but it is related to [[13edo|13-EDO]] and [[18edo|18-EDO]] and produces [[MOSScales|MOS scales]] of 5 and 8 notes: 5 5 4 5 4 (the [[3L 2s|"anti-pentatonic"]]) and 4 1 4 1 4 4 1 4 (the "quarter-tone" version of the Blackwood/[http://en.wikipedia.org/wiki/Paul_Rapoport_%28music_critic%29 Rapoport]/Wilson 13-EDO "subminor" scale). Alternatively we can treat this temperament as a 2.9.21 subgroup, and instead of calling 9 degrees of 23-EDO a Sub-"4/3", we can call it 21/16. Here three 21/16's gets us to 9/4, meaning 1029/1024 is tempered out. This allows us to treat a triad of 0-4-9 degrees of 23-EDO as an approximation to 16:18:21, and 0-5-9 as 1/(16:18:21); both of these triads are abundant in the 8-note MOS scale. | ||
== Selected just intervals == | |||
{| class="wikitable center-all" | |||
|- | |||
|+ 23-EDO Approximation of Primary Intervals | |||
|- | |||
! colspan="2" | Prime number | |||
! 3 | |||
! 5 | |||
! 7 | |||
! 11 | |||
! 13 | |||
! 17 | |||
! 19 | |||
! 23 | |||
|- | |||
! rowspan="2" | Error | |||
! absolute ([[cent|¢]]) | |||
| -23.69 | |||
| -21.10 | |||
| +22.48 | |||
| +22.60 | |||
| -5.75 | |||
| -0.61 | |||
| +15.53 | |||
| -2.19 | |||
|- | |||
! [[Relative error|relative]] (%) | |||
| -45.4 | |||
| -40.4 | |||
| +43.1 | |||
| +43.3 | |||
| -11.0 | |||
| -1.2 | |||
| +29.8 | |||
| -4.2 | |||
|- | |||
! colspan="2" | Degree ([[octave reduction|reduced]]) | |||
| 36 (13) | |||
| 53 (7) | |||
| 65 (19) | |||
| 80 (11) | |||
| 85 (16) | |||
| 94 (2) | |||
| 98 (6) | |||
| 104 (12) | |||
|} | |||
== Notation == | == Notation == |