31st-octave temperaments: Difference between revisions
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All temperaments on this page have a period that is 1/31th of an octave. | All temperaments on this page have a period that is 1/31th of an octave. | ||
By the ''31-3-comma'' is meant 617673396283947/562949953421312 = {{monzo| -49 31 }}, the amount (160.605 [[cent]]s) by which 31 just perfect fifths ([[3/2]]) exceed 18 [[octave]]s. This may not seem like much of a comma, but since [[31edo]] is such a strong 7-limit system, 11- and 13-limit temperaments based on the cycle of 31 fifths actually make sense. | By the ''31-3-comma'' is meant 617673396283947/562949953421312 = {{monzo| -49 31 }}, the amount (160.605 [[cent]]s) by which 31 just perfect fifths ([[3/2]]) exceed 18 [[octave]]s. This may not seem like much of a comma, but since [[31edo]] is such a strong 7-limit system, 11- and 13-limit temperaments based on the cycle of 31 fifths actually make sense. This approach leads to the prajapati temperament and the gallium temperament. | ||
31edo is accurate for harmonics 5 and 7, the 31-5-comma ({{monzo| 72 0 -31 }}, the amount by which 31 just major thirds ([[5/4]]) fall short of 10 octaves) and the 31-7-comma ({{monzo| -87 0 0 31 }}, the amount by which 31 septimal whole tone ([[8/7]]) fall short of 6 octaves) is tempered out by {{Val list| 31, 62, 93, 124, 155, 186, 217, 248, 279, 310, 341, 372, 403, 434, 465, 496, and 527edo }}. Tempering out these commas leads to the birds temperament. | 31edo is accurate for harmonics 5 and 7, the 31-5-comma ({{monzo| 72 0 -31 }}, the amount by which 31 just major thirds ([[5/4]]) fall short of 10 octaves) and the 31-7-comma ({{monzo| -87 0 0 31 }}, the amount by which 31 septimal whole tone ([[8/7]]) fall short of 6 octaves) is tempered out by {{Val list| 31, 62, 93, 124, 155, 186, 217, 248, 279, 310, 341, 372, 403, 434, 465, 496, and 527edo }}. Tempering out these commas leads to the birds temperament. | ||
== Birds == | |||
The birds temperament tempers out the 31-5 comma, {{monzo| 72 0 -31 }}, and the 31-7 comma, ({{monzo| -87 0 0 31 }}. The name comes from Isaiah 31:5 "As birds flying, so wil the Lord of hostes defend Ierusalem, defending also hee will deliuer it, and passing ouer, he will preserue it." | |||
Subgroup: 2.3.5.7 | |||
[[Comma list]]: 3136/3125, 823543/819200 | |||
[[Mapping]]: [{{val|31 49 72 87}}, {{val|0 1 0 0}}] | |||
{{multival|legend=1|31 0 0 -72 -87 0}} | |||
[[POTE generator]]: ~1029/1024 = 5.1551 | |||
{{Val list|legend=1| 31, 124, 155, 186, 217, 248, 465 }} | |||
[[Badness]]: 0.099928 | |||
=== 11-limit === | |||
Subgroup: 2.3.5.7.11 | |||
Comma list: 441/440, 3136/3125, 41503/41472 | |||
Mapping: [{{val|31 49 72 87 107}}, {{val|0 1 0 0 2}}] | |||
POTE generator: ~385/384 = 4.9377 | |||
Vals: {{Val list| 31, 186e, 217, 248, 961cd }} | |||
Badness: 0.039921 | |||
=== 13-limit === | |||
Subgroup: 2.3.5.7.11.13 | |||
Comma list: 441/440, 1001/1000, 3136/3125, 13720/13689 | |||
Mapping: [{{val|31 49 72 87 107 115}}, {{val|0 1 0 0 2 -2}}] | |||
POTE generator: ~385/384 = 5.1703 | |||
Vals: {{Val list| 31, 186e, 217, 248, 465 }} | |||
Badness: 0.035680 | |||
=== 17-limit === | |||
Subgroup: 2.3.5.7.11.13.17 | |||
Comma list: 441/440, 833/832, 1001/1000, 1225/1224, 3136/3125 | |||
Mapping: [{{val|31 49 72 87 107 115 127}}, {{val|0 1 0 0 2 -2 -2}}] | |||
POTE generator: ~385/384 = 5.2248 | |||
Vals: {{Val list| 31, 186e, 217, 248, 465 }} | |||
Badness: 0.025890 | |||
=== 19-limit === | |||
Subgroup: 2.3.5.7.11.13.17.19 | |||
Comma list: 343/342, 441/440, 476/475, 833/832, 1001/1000, 1445/1444 | |||
Mapping: [{{val|31 49 72 87 107 115 127 132}}, {{val|0 1 0 0 2 -2 -2 -2}}] | |||
POTE generator: ~385/384 = 5.3169 | |||
Vals: {{Val list| 31, 186e, 217, 248h, 465h }} | |||
Badness: 0.021271 | |||
== Prajapati == | == Prajapati == | ||
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Badness: 0.019963 | Badness: 0.019963 | ||
[[Category:31edo]] | [[Category:31edo]] | ||