37edo: Difference between revisions
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| Augmented 1sn = 6\37 = 195¢ | | Augmented 1sn = 6\37 = 195¢ | ||
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''' | '''37EDO''' is a scale derived from dividing the octave into 37 equal steps. It is the 12th [[prime_numbers|prime]] EDO, following [[31edo|31EDO]] and coming before [[41edo|41EDO]]. | ||
== Theory == | == Theory == | ||
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|} | |} | ||
Using its best (and sharp) fifth, | Using its best (and sharp) fifth, 37EDO tempers out 250/243, making it a variant of [[porcupine]] temperament. It is the optimal patent val for [[Porcupine family #Porcupinefish|porcupinefish]], which is about as accurate as "13-limit porcupine" will be. Using its alternative flat fifth, it tempers out 16875/16384, making it a [[Negri|negri]] tuning. It also tempers out 2187/2000, resulting in a temperament where three minor whole tones make up a fifth ([[gorgo]]/[[laconic]]). | ||
37EDO is also a very accurate equal tuning for [[undecimation]] temperament, which has a generator of about 519 cents; 2 generators lead to 29/16; 3 generators to 32/13; 6 generators to a 10 cent sharp 6/1; 8 generators to a very accurate 11/1 and 10 generators to 20/1. It has a 7L+2s nonatonic MOS, which in 37EDO scale degrees is 0, 1, 6, 11, 16, 17, 22, 27, 32, a scale structure reminiscent of mavila; as well as a 16 note MOS. | |||
=== Subgroups === | === Subgroups === | ||
37EDO offers close approximations to [[Overtone series|harmonics]] 5, 7, 11, and 13 [and a usable approximation of 9 as well]. | |||
12\37 = 389.2 cents | 12\37 = 389.2 cents | ||
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26\37 = 843.2 cents | 26\37 = 843.2 cents | ||
[6\ | [6\37 = 194.6 cents] | ||
This means 37 is quite accurate on the 2.5.7.11.13 subgroup, where it shares the same tuning as | This means 37 is quite accurate on the 2.5.7.11.13 subgroup, where it shares the same tuning as 111EDO. In fact, on the larger [[k*N_subgroups|3*37 subgroup]] 2.27.5.7.11.13.51.57 subgroup not only shares the same tuning as 19-limit 111EDO, it tempers out the same commas. A simpler but less accurate approach is to use the 2*37-subgroup, 2.9.7.11.13.17.19, on which it has the same tuning and commas as 74EDO. | ||
=== The Two Fifths === | === The Two Fifths === | ||
The just [[perfect fifth]] of frequency ratio 3:2 is not well-approximated, and falls between two intervals in | The just [[perfect fifth]] of frequency ratio 3:2 is not well-approximated, and falls between two intervals in 37EDO: | ||
The flat fifth is 21\37 = 681.1 cents (37b val) | The flat fifth is 21\37 = 681.1 cents (37b val) | ||
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If the minor third of 259.5 cents is mapped to 7/6, this superpythagorean scale can be thought of as a variant of [[The_Biosphere|Biome]] temperament. | If the minor third of 259.5 cents is mapped to 7/6, this superpythagorean scale can be thought of as a variant of [[The_Biosphere|Biome]] temperament. | ||
Interestingly, the "major thirds" of both systems are not 12\37 = 389.2¢, the closest approximation to 5/4 available in | Interestingly, the "major thirds" of both systems are not 12\37 = 389.2¢, the closest approximation to 5/4 available in 37EDO. | ||
37EDO has great potential as a near-just xenharmonic system, with high-prime chords such as 8:10:11:13:14 with no perfect fifths available for common terrestrial progressions. The 9/8 approximation is usable but introduces error. One may choose to treat either of the intervals close to 3/2 as 3/2, introducing additional approximations with considerable error (see interval table below). | |||
== Intervals == | == Intervals == | ||
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| 1 | | 1 | ||
| 32.43 | | 32.43 | ||
| | | [[55/54]], [[56/55]] | ||
| | | | ||
| | | | ||
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| 97.30 | | 97.30 | ||
| [[55/52]] | | [[55/52]] | ||
| | | [[16/15]] | ||
| | | | ||
| | | | ||
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| 129.73 | | 129.73 | ||
| [[14/13]] | | [[14/13]] | ||
| [[13/12]] | | [[13/12]], [[15/14]] | ||
| [[12/11]] | | [[12/11]] | ||
| | | | ||
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| 259.46 | | 259.46 | ||
| | | | ||
| [[7/6]] | | [[7/6]], [[15/13]] | ||
| | | | ||
| | | | ||
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| 551.35 | | 551.35 | ||
| [[11/8]] | | [[11/8]] | ||
| | | [[15/11]] | ||
| | | | ||
| [[18/13]] | | [[18/13]] | ||
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| 648.65 | | 648.65 | ||
| [[16/11]] | | [[16/11]] | ||
| | | [[22/15]] | ||
| | | | ||
| [[13/9]] | | [[13/9]] | ||
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| 940.54 | | 940.54 | ||
| | | | ||
| [[12/7]] | | [[12/7]], [[26/15]] | ||
| | | | ||
| | | | ||
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| 1070.27 | | 1070.27 | ||
| [[13/7]] | | [[13/7]] | ||
| [[24/13]] | | [[24/13]], [[28/15]] | ||
| [[11/6]] | | [[11/6]] | ||
| | | | ||
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| 1102.70 | | 1102.70 | ||
| [[104/55]] | | [[104/55]] | ||
| | | [[15/8]] | ||
| | | | ||
| | | | ||
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=== Temperament measures === | === Temperament measures === | ||
The following table shows [[TE temperament measures]] (RMS normalized by the rank) of | The following table shows [[TE temperament measures]] (RMS normalized by the rank) of 37EDO. | ||
{| class="wikitable center-all" | {| class="wikitable center-all" | ||
! colspan="2" | | ! colspan="2" | | ||
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|} | |} | ||
* | * 37EDO is most prominent in the no-3 11-, 13-, 17-, 19- and 23-limit subgroups. The next EDO that does better in these subgroups is 109, 581, 103, 124 and 93, respectively. | ||
== Scales == | == Scales == | ||
* [[MOS_Scales_of_37edo|MOS Scales of 37edo]] | * [[MOS_Scales_of_37edo|MOS Scales of 37edo]] | ||
* [[roulette6]] | * [[roulette6]] | ||
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|- | |- | ||
| 5\37 | | 5\37 | ||
| [[Porcupine]]/[[ | | [[Porcupine]]/[[The Biosphere #Oceanfront-Oceanfront Children-Porcupinefish|porcupinefish]] | ||
| | | | ||
|- | |- | ||
| 6\37 | | 6\37 | ||
| colspan="2" | [[ | | colspan="2" | [[Chromatic pairs #Roulette|Roulette]] | ||
|- | |- | ||
| 7\37 | | 7\37 | ||
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| 9\37 | | 9\37 | ||
| | | | ||
| [[ | | [[Chromatic pairs #Gariberttet|Gariberttet]] | ||
|- | |- | ||
| 10\37 | | 10\37 | ||
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|- | |- | ||
| 13\37 | | 13\37 | ||
| [[ | | [[Meantone family #Squares|Squares]] | ||
| | | | ||
|- | |- | ||
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|- | |- | ||
| 15\37 | | 15\37 | ||
| [[ | | [[The Biosphere#Oceanfront-Oceanfront Children-Ultrapyth|Ultrapyth]], '''not''' [[superpyth]] | ||
| | | | ||
|- | |- | ||
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== Music == | == Music == | ||
* [http://www.akjmusic.com/audio/toccata_bianca_37edo.mp3 Toccata Bianca | * [http://www.akjmusic.com/audio/toccata_bianca_37edo.mp3 Toccata Bianca 37EDO] by [http://www.akjmusic.com/ Aaron Krister Johnson] | ||
* [http://andrewheathwaite.bandcamp.com/track/shorn-brown Shorn Brown] [http://micro.soonlabel.com/gene_ward_smith/Others/Heathwaite/Newbeams/Andrew%20Heathwaite%20-%20Newbeams%20-%2002%20Shorn%20Brown.mp3 play] and [http://andrewheathwaite.bandcamp.com/track/jellybear Jellybear] [http://micro.soonlabel.com/gene_ward_smith/Others/Heathwaite/Newbeams/Andrew%20Heathwaite%20-%20Newbeams%20-%2003%20Jellybear.mp3 play] by [[Andrew Heathwaite]] | * [http://andrewheathwaite.bandcamp.com/track/shorn-brown Shorn Brown] [http://micro.soonlabel.com/gene_ward_smith/Others/Heathwaite/Newbeams/Andrew%20Heathwaite%20-%20Newbeams%20-%2002%20Shorn%20Brown.mp3 play] and [http://andrewheathwaite.bandcamp.com/track/jellybear Jellybear] [http://micro.soonlabel.com/gene_ward_smith/Others/Heathwaite/Newbeams/Andrew%20Heathwaite%20-%20Newbeams%20-%2003%20Jellybear.mp3 play] by [[Andrew Heathwaite]] | ||
* [http://micro.soonlabel.com/gene_ward_smith/Others/Monzo/monzo_kog-sisters_2014-0405.mp3 The Kog Sisters] by [[Joe Monzo]] | * [http://micro.soonlabel.com/gene_ward_smith/Others/Monzo/monzo_kog-sisters_2014-0405.mp3 The Kog Sisters] by [[Joe Monzo]] | ||
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== Links == | == Links == | ||
* [http://tonalsoft.com/enc/number/37-edo/37edo.aspx 37edo at Tonalsoft] | * [http://tonalsoft.com/enc/number/37-edo/37edo.aspx 37edo at Tonalsoft] | ||
[[Category:37edo| ]] <!-- main article --> | |||
[[Category:Equal divisions of the octave]] | [[Category:Equal divisions of the octave]] | ||
[[Category:Prime EDO]] | [[Category:Prime EDO]] | ||
[[Category:Subgroup]] | [[Category:Subgroup]] |