31edo: Difference between revisions

ArrowHead294 (talk | contribs)
ArrowHead294 (talk | contribs)
mNo edit summary
Line 12: Line 12:


== Theory ==
== Theory ==
31edo's perfect fifth is flat of the just interval [[3/2]] (over five cents), as befits a tuning [[support]]ing [[meantone]], but the major third is less than a cent sharp of just [[5/4]], making it slightly sharp of [[quarter-comma meantone]]. 31's approximation of [[7/4]], a cent flat, is also very close to just. It is a very tone-efficient melodic approximation of the [[11-limit]] (and specifically the [[11-odd-limit]]), although it conflates [[9/7]] with [[14/11]] and [[11/8]] with [[15/11]]. Many [[7-limit]] JI scales are well-approximated in 31 (with tempering, of course). It also maps all [[15-odd-limit]] intervals consistently, with the sole exceptions of [[13/9]], [[13/11]], [[18/13]], and [[22/13]].
31edo's perfect fifth is flat of the just interval [[3/2]] by 5.2{{c}}, as befits a tuning [[support]]ing [[meantone]], but the major third is less than a cent sharp of just [[5/4]], making it slightly sharp of [[quarter-comma meantone]]. 31's approximation of [[7/4]], a cent flat, is also very close to just. It is a very tone-efficient melodic approximation of the [[11-limit]] (and specifically the [[11-odd-limit]]), although it conflates [[9/7]] with [[14/11]] and [[11/8]] with [[15/11]]. Many [[7-limit]] JI scales are well-approximated in 31 (with tempering, of course). It also maps all [[15-odd-limit]] intervals consistently, with the sole exceptions of [[13/9]], [[13/11]], [[18/13]], and [[22/13]].


Because of the near-just 5/4 and 7/4 and because the 11th harmonic is almost twice as flat as the 3rd harmonic, 31edo is relatively quite accurate and is [[The Riemann Zeta Function and Tuning #Zeta EDO lists|the 6th zeta integral edo, the 7th zeta gap edo, a zeta peak edo, and a zeta peak integer edo]], meaning it is a [[The Riemann Zeta Function and Tuning #Zeta EDO lists|strict zeta edo]]. Other ways in which 31edo is especially accurate is that it represents a record in [[Pepper ambiguity]] in the 7-, 9-, and [[11-odd-limit]], which it is [[consistent]] through, and that it is the first [[Trivial temperament|non-trivial]] edo to be consistent in the 11-[[odd prime sum limit|odd-prime-sum-limit]].
Because of the near-just 5/4 and 7/4 and because the 11th harmonic is almost twice as flat as the 3rd harmonic, 31edo is relatively quite accurate and is [[The Riemann Zeta Function and Tuning #Zeta EDO lists|the 6th zeta integral edo, the 7th zeta gap edo, a zeta peak edo, and a zeta peak integer edo]], meaning it is a [[The Riemann Zeta Function and Tuning #Zeta EDO lists|strict zeta edo]]. Other ways in which 31edo is especially accurate is that it represents a record in [[Pepper ambiguity]] in the 7-, 9-, and [[11-odd-limit]], which it is [[consistent]] through, and that it is the first [[Trivial temperament|non-trivial]] edo to be consistent in the 11-[[odd prime sum limit|odd-prime-sum-limit]].
Line 18: Line 18:
One step of 31edo, measuring about 38.7¢, is called a [[diesis]] because it stands in for several intervals called "dieses" (most notably, [[128/125]] and [[648/625]]) which are tempered out in [[12edo]]. The diesis is a defining sound of 31edo; when it does not appear directly in a scale, it often shows up as the difference between two or more intervals of a similar size. The diesis is demonstrated in [[SpiralProgressions]]. [[Zhea Erose]]'s 31edo music uses the interval frequently.  
One step of 31edo, measuring about 38.7¢, is called a [[diesis]] because it stands in for several intervals called "dieses" (most notably, [[128/125]] and [[648/625]]) which are tempered out in [[12edo]]. The diesis is a defining sound of 31edo; when it does not appear directly in a scale, it often shows up as the difference between two or more intervals of a similar size. The diesis is demonstrated in [[SpiralProgressions]]. [[Zhea Erose]]'s 31edo music uses the interval frequently.  


31edo is close to a circle made by stacking 31 pure [[17/13]] subfourths. A circle of 31 pure 17/13's closes with an error of only 2.74 cents ([[relative error]] 7.1%). Remarkably, 31edo tempers out [[83521/83486]], the 0.7-cent difference between a stack of four 17/13's and a stack of one 19/13 and one 2/1, giving 31edo's [[oneirotonic]] (5L 3s) [[mos]] accurate 13:17:19 chords.
31edo is close to a circle made by stacking 31 pure [[17/13]] subfourths. A circle of 31 pure 17/13's closes with an error of only 2.74 cents ([[relative error]] 7.1%). Remarkably, 31edo tempers out [[83521/83486]], the 0.7-cent difference between a stack of four 17/13's and a stack of one 19/13 and one 2/1, giving 31edo's [[oneirotonic]] (5L 3s) [[mos]] accurate 13:17:19 chords.


=== Prime harmonics ===
=== Prime harmonics ===
Line 473: Line 473:
| rowspan="2" | minor
| rowspan="2" | minor
| fourthward wa
| fourthward wa
| {{monzo|a b}} where {{nowrap|b < −1}}
| {{monzo|a b}} where {{nowrap|b < −1}}
| 32/27, 16/9
| 32/27, 16/9
|-
|-
Line 653: Line 653:
[[File:31edo CoF semi and sesqui.png|none|thumb|500x500px]]
[[File:31edo CoF semi and sesqui.png|none|thumb|500x500px]]


===Sagittal notation===
=== Sagittal notation ===
This notation uses the same sagittal sequence as EDOs [[17edo#Sagittal notation|17]], [[24edo#Sagittal notation|24]], and [[38edo#Sagittal notation|38]], and is a subset of the notation for [[62edo#Sagittal notation|62-EDO]].
This notation uses the same sagittal sequence as EDOs [[17edo#Sagittal notation|17]], [[24edo#Sagittal notation|24]], and [[38edo#Sagittal notation|38]], and is a subset of the notation for [[62edo#Sagittal notation|62-EDO]].
====Evo flavor====
==== Evo flavor ====
 
<imagemap>
<imagemap>
File:31-EDO_Evo_Sagittal.svg
File:31-EDO_Evo_Sagittal.svg
Line 666: Line 665:
</imagemap>
</imagemap>


====Revo flavor====
==== Revo flavor ====
 
<imagemap>
<imagemap>
File:31-EDO_Revo_Sagittal.svg
File:31-EDO_Revo_Sagittal.svg
Line 681: Line 679:
[[File:31edo Sagittal.png|800px]]
[[File:31edo Sagittal.png|800px]]


====Evo-SZ flavor====
==== Evo-SZ flavor ====
 
<imagemap>
<imagemap>
File:31-EDO_Evo-SZ_Sagittal.svg
File:31-EDO_Evo-SZ_Sagittal.svg
Line 717: Line 714:
The fact that 31edo has meantone diatonic and chromatic scales is well-known, but some other [[MOS]]es and MOS chains{{clarify}} are also useful:
The fact that 31edo has meantone diatonic and chromatic scales is well-known, but some other [[MOS]]es and MOS chains{{clarify}} are also useful:
* 9\31, the neutral third, generates [[ultrasoft]] [[mosh]] and [[superhard]] [[dicotonic]] MOSes.
* 9\31, the neutral third, generates [[ultrasoft]] [[mosh]] and [[superhard]] [[dicotonic]] MOSes.
* 11\31, the supermajor third or diminished fourth, generates a [[TAMNAMS|parahard]] [[sensoid]] scale with resolution from neutral thirds, sixths, and sevenths to perfect fourths, fifths, and octaves, and a [[semihard]] [[3L 8s]] scale with a jagged-but-chromatic feel.
* 11\31, the supermajor third or diminished fourth, generates a [[TAMNAMS|parahard]] [[sensoid]] scale with resolution from neutral thirds, sixths, and sevenths to perfect fourths, fifths, and octaves, and a [[semihard]] [[3L&nbsp;8s]] scale with a jagged-but-chromatic feel.
* 12\31 generator generates a [[semihard]] [[oneirotonic]] scale, similar to the 5L 3s scale in [[13edo]] but with the 9/8, 5/4 and 7/6 better in tune and with the flat fifth close to [[19/13]].
* 12\31 generator generates a [[semihard]] [[oneirotonic]] scale, similar to the 5L&nbsp;3s scale in [[13edo]] but with the 9/8, 5/4 and 7/6 better in tune and with the flat fifth close to [[19/13]].
* A chain of 5\31 whole tones is exceptionally rich in 4:5:7 chords, which are approximated very well in 31edo.
* A chain of 5\31 whole tones is exceptionally rich in 4:5:7 chords, which are approximated very well in 31edo.
* If you're fond of orwell tetrads (which are also found in 31edo's oneirotonic), you will like the 7\31 (271.0¢) subminor third generator. The [[ultrasoft]] 9-tone [[4L 5s|orwelloid (4L 5s)]] MOS could be treated as a 9-tone well temperament.
* If you're fond of orwell tetrads (which are also found in 31edo's oneirotonic), you will like the 7\31 (271.0¢) subminor third generator. The [[ultrasoft]] 9-tone orwelloid [[4L&nbsp;5s]] MOS could be treated as a 9-tone well temperament.
* It has close approximations to [[6edf]] (&rarr; [[miracle]]) and [[9edf]] (&rarr; [[Carlos Alpha]]), fifth-equivalent equal divisions that hit many good JI approximations.
* It has close approximations to [[6edf]] (&rarr; [[miracle]]) and [[9edf]] (&rarr; [[Carlos Alpha]]), fifth-equivalent equal divisions that hit many good JI approximations.


Line 1,191: Line 1,188:
* [[List of 31et rank two temperaments by badness]]
* [[List of 31et rank two temperaments by badness]]
* [[List of edo-distinct 31et rank two temperaments]]
* [[List of edo-distinct 31et rank two temperaments]]
* [[Syntonic&ndash;31 equivalence continuum]]
* [[Syntonic–31 equivalence continuum]]


{| class="wikitable center-1"
{| class="wikitable center-1"
Line 1,210: Line 1,207:
| 2\31
| 2\31
| 77.42
| 77.42
| [[1L 14s]], [[15L 1s]]
| [[1L&nbsp;14s]], [[15L&nbsp;1s]]
| [[Valentine]] / [[lupercalia]]
| [[Valentine]] / [[lupercalia]]
| (P8, P5/9)
| (P8, P5/9)
Line 1,216: Line 1,213:
| 3\31
| 3\31
| 116.13
| 116.13
| [[1L 9s]], [[10L 1s]], [[10L 11s]]
| [[1L&nbsp;9s]], [[10L&nbsp;1s]], [[10L&nbsp;11s]]
| [[Mercy]] / [[miracle]]
| [[Mercy]] / [[miracle]]
| (P8, P5/6)
| (P8, P5/6)
Line 1,222: Line 1,219:
| 4\31
| 4\31
| 154.84
| 154.84
| [[1L 6s]], [[7L 1s]], <br>[[8L 7s]], [[8L 15s]]
| [[1L&nbsp;6s]], [[7L&nbsp;1s]], <br>[[8L&nbsp;7s]], [[8L&nbsp;15s]]
| [[Greeley]] / [[nusecond]]
| [[Greeley]] / [[nusecond]]
| (P8, P11/11)
| (P8, P11/11)
Line 1,228: Line 1,225:
| 5\31
| 5\31
| 193.55
| 193.55
| [[1L 5s]], [[6L 1s]], [[6L 7s]], <br>[[6L 13s]], [[6L 19s]]
| [[1L&nbsp;5s]], [[6L&nbsp;1s]], [[6L&nbsp;7s]], <br>[[6L&nbsp;13s]], [[6L&nbsp;19s]]
| [[Luna]] / [[didacus]] / [[hemithirds]] /<br>[[hemiwürschmidt]] / [[tutone]]
| [[Luna]] / [[didacus]] / [[hemithirds]] /<br>[[hemiwürschmidt]] / [[tutone]]
| (P8, ccP4/15)
| (P8, ccP4/15)
Line 1,234: Line 1,231:
| 6\31
| 6\31
| 232.26
| 232.26
| [[1L 4s]], [[5L 1s]], [[5L 6s]], <br>[[5L 11s]], [[5L 16s]], [[5L 21s]]
| [[1L&nbsp;4s]], [[5L&nbsp;1s]], [[5L&nbsp;6s]], <br>[[5L&nbsp;11s]], [[5L&nbsp;16s]], [[5L&nbsp;21s]]
| [[Mothra]] / [[mosura]]<br>[[Quadrawell]]
| [[Mothra]] / [[mosura]]<br>[[Quadrawell]]
| (P8, P5/3)
| (P8, P5/3)
Line 1,240: Line 1,237:
| 7\31
| 7\31
| 270.97
| 270.97
| [[1L 3s]], [[4L 1s]], [[4L 5s]], <br>[[9L 4s]], [[9L 13s]]
| [[1L&nbsp;3s]], [[4L&nbsp;1s]], [[4L&nbsp;5s]], <br>[[9L&nbsp;4s]], [[9L&nbsp;13s]]
| [[Orson]] / [[orwell]] / [[winston]]
| [[Orson]] / [[orwell]] / [[winston]]
| (P8, P12/7)
| (P8, P12/7)
Line 1,246: Line 1,243:
| 8\31
| 8\31
| 309.68
| 309.68
| [[3L 1s]], [[4L 3s]], [[4L 7s]], <br>[[4L 11s]], [[4L 15s]], [[4L 19s]], <br>[[4L 23s]]
| [[3L&nbsp;1s]], [[4L&nbsp;3s]], [[4L&nbsp;7s]], <br>[[4L&nbsp;11s]], [[4L&nbsp;15s]], [[4L&nbsp;19s]], <br>[[4L&nbsp;23s]]
| [[Myna]]<br>[[Triwell]]
| [[Myna]]<br>[[Triwell]]
| (P8, ccP5/10)
| (P8, ccP5/10)
Line 1,252: Line 1,249:
| 9\31
| 9\31
| 348.39
| 348.39
| [[3L 1s]], [[3L 4s]], [[7L 3s]], <br>[[7L 10s]], [[7L 17s]]
| [[3L&nbsp;1s]], [[3L&nbsp;4s]], [[7L&nbsp;3s]], <br>[[7L&nbsp;10s]], [[7L&nbsp;17s]]
| [[Mohaha]] / [[vicentino]] /<br>[[mohajira]] / [[migration]]
| [[Mohaha]] / [[vicentino]] /<br>[[mohajira]] / [[migration]]
| (P8, P5/2)
| (P8, P5/2)
Line 1,258: Line 1,255:
| 10\31
| 10\31
| 387.10
| 387.10
| [[3L 1s]], [[3L 4s]], [[3L 7s]], <br>[[3L 10s]], [[3L 13s]], [[3L 16s]], <br>[[3L 19s]], [[3L 22s]], [[3L 25s]]
| [[3L&nbsp;1s]], [[3L&nbsp;4s]], [[3L&nbsp;7s]], <br>[[3L&nbsp;10s]], [[3L&nbsp;13s]], [[3L&nbsp;16s]], <br>[[3L&nbsp;19s]], [[3L&nbsp;22s]], [[3L&nbsp;25s]]
| [[Würschmidt]] / [[worschmidt]]
| [[Würschmidt]] / [[worschmidt]]
| (P8, ccP5/8)
| (P8, ccP5/8)
Line 1,264: Line 1,261:
| 11\31
| 11\31
| 425.81
| 425.81
| [[3L 2s]], [[3L 5s]], [[3L 8s]], <br>[[3L 11s]], [[14L 3s]]
| [[3L&nbsp;2s]], [[3L&nbsp;5s]], [[3L&nbsp;8s]], <br>[[3L&nbsp;11s]], [[14L&nbsp;3s]]
| [[Squares]] / [[sentinel]]
| [[Squares]] / [[sentinel]]
| (P8, P11/4)
| (P8, P11/4)
Line 1,270: Line 1,267:
| 12\31
| 12\31
| 464.52
| 464.52
| [[3L 2s]], [[5L 3s]], <br>[[5L 8s]], [[13L 5s]]
| [[3L&nbsp;2s]], [[5L&nbsp;3s]], <br>[[5L&nbsp;8s]], [[13L&nbsp;5s]]
| [[A-Team]]<br>[[Semisept]]
| [[A-Team]]<br>[[Semisept]]
| (P8, c<sup>5</sup>P4/14)
| (P8, c<sup>5</sup>P4/14)
Line 1,276: Line 1,273:
| 13\31
| 13\31
| 503.23
| 503.23
| [[2L 3s]], [[5L 2s]], <br>[[7L 5s]], [[12L 7s]]
| [[2L&nbsp;3s]], [[5L&nbsp;2s]], <br>[[7L&nbsp;5s]], [[12L&nbsp;7s]]
| [[Meantone]] / [[meanpop]]
| [[Meantone]] / [[meanpop]]
| (P8, P5)
| (P8, P5)
Line 1,282: Line 1,279:
| 14\31
| 14\31
| 541.94
| 541.94
| [[2L 3s]], [[2L 5s]], [[2L 7s]], <br>[[9L 2s]], [[11L 9s]]
| [[2L&nbsp;3s]], [[2L&nbsp;5s]], [[2L&nbsp;7s]], <br>[[9L&nbsp;2s]], [[11L&nbsp;9s]]
| [[Casablanca]]<br>[[Cypress]]<br>[[Oracle]]
| [[Casablanca]]<br>[[Cypress]]<br>[[Oracle]]
| (P8, c<sup>5</sup>P4/12)
| (P8, c<sup>5</sup>P4/12)
Line 1,288: Line 1,285:
| 15\31
| 15\31
| 580.65
| 580.65
| [[2L 3s]], [[2L 5s]], [[2L 7s]], <br>[[2L 9s]], [[2L 11s]], [[2L 13s]], <br>[[2L 15s]], [[2L 17s]], [[2L 19s]], <br>[[2L 21s]], [[2L 23s]], [[2L 25s]], <br>[[2L 27s]]
| [[2L&nbsp;3s]], [[2L&nbsp;5s]], [[2L&nbsp;7s]], <br>[[2L&nbsp;9s]], [[2L&nbsp;11s]], [[2L&nbsp;13s]], <br>[[2L&nbsp;15s]], [[2L&nbsp;17s]], [[2L&nbsp;19s]], <br>[[2L&nbsp;21s]], [[2L&nbsp;23s]], [[2L&nbsp;25s]], <br>[[2L&nbsp;27s]]
| [[Tritonic]] / [[tritoni]]
| [[Tritonic]] / [[tritoni]]
| (P8, ccP4/5)
| (P8, ccP4/5)
|}
|}
<nowiki/>* [[Normal lists|Octave-reduced form]], reduced to the first half-octave, and [[Normal lists|minimal form]] in parentheses if it is distinct
<nowiki/>* [[Normal lists|Octave-reduced form]], reduced to the first half-octave, and [[Normal lists|minimal form]] in parentheses if distinct


== Instruments ==
== Instruments ==
Line 1,315: Line 1,312:
* [[Pentachords of 31edo]]
* [[Pentachords of 31edo]]
* [[Tricesimoprimal Tetrachordal Tesseract]]
* [[Tricesimoprimal Tetrachordal Tesseract]]
* [[MicroPedagogyCollective]] &ndash; is at work (as of 2012) producing demonstrative material which will encourage and enable more people to learn this system. There have been two [[ThirtyOneToneSinginCamp]]s as well.
* [[MicroPedagogyCollective]] is at work (as of 2012) producing demonstrative material which will encourage and enable more people to learn this system. There have been two [[ThirtyOneToneSinginCamp]]s as well.
* [[CG-31]]
* [[CG-31]]


Line 1,340: Line 1,337:


=== Videos ===
=== Videos ===
* [https://youtu.be/E_VD3tqwCAM ''Quarter sharps and flats in the same diatonic key signature'' &ndash; Youtube] by [[Stephen Weigel]] &ndash; a list of diatonic key signatures and major scales in 31edo (including semi- and sesqui-sharps); and docs in its description.
* [https://youtu.be/E_VD3tqwCAM ''Quarter sharps and flats in the same diatonic key signature'' Youtube] by [[Stephen Weigel]] a list of diatonic key signatures and major scales in 31edo (including semi- and sesqui-sharps); and docs in its description.
* [https://www.youtube.com/watch?v=7cv-nuSjbY4&list=PLiWv7dE90L6CsQmQySVdAiRSIIDaAymiJ&pp=iAQB Playlist of 31edo music theory videos on YouTube] by [[Zhea Erose]]
* [https://www.youtube.com/watch?v=7cv-nuSjbY4&list=PLiWv7dE90L6CsQmQySVdAiRSIIDaAymiJ&pp=iAQB Playlist of 31edo music theory videos on YouTube] by [[Zhea Erose]]


=== Software ===
=== Software ===
* [http://31et.com/keyboard.php Virtual Piano Keyboard in 31-Tone Equal Temperament]
* [http://31et.com/keyboard.php Virtual Piano Keyboard in 31-Tone Equal Temperament]
* [http://www.warmplace.ru/forum/viewtopic.php?f=9&t=4750 31EDO Piano &ndash; Mini synthesizer in Pixilang]
* [http://www.warmplace.ru/forum/viewtopic.php?f=9&t=4750 31EDO Piano Mini synthesizer in Pixilang]


=== Diagrams ===
=== Diagrams ===