20th-octave temperaments: Difference between revisions
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{{Infobox fractional-octave|20}} | {{Infobox fractional-octave|20}} | ||
[[20edo]] (in isolation) is not a particularly harmonically interesting edo, but some of its multiples have high consistency limits (17-odd-limit and higher), and therefore are worthy of being considered in terms of rank-2 temperaments | [[20edo]] (in isolation) is not a particularly harmonically interesting edo, but some of its multiples have high consistency limits (17-odd-limit and higher), and therefore are worthy of being considered in terms of rank-2 temperaments. | ||
In the [[17-limit]], one step of 20edo is extremely close to [[88/85]], which serves as a period in two of these temperaments – | It is worth noting that [[degrees]] (discussed elsewhere) is a no-31's [[41-limit]] temperament which serves as a well-temperament of [[80edo]] in the corresponding subgroup, as a 60L 20s mos is sufficient for finding all its primes. | ||
In the [[17-limit]], one step of 20edo is extremely close to [[88/85]], which serves as a period in two of these temperaments – soviet ferris wheel and calcium. | |||
Temperaments discussed elsewhere include | Temperaments discussed elsewhere include | ||
* ''[[Degrees]]'' → [[Hemimage temperaments #Degrees|Hemimage temperaments]] | * ''[[Degrees]]'' → [[Hemimage temperaments #Degrees|Hemimage temperaments]] | ||
== Soviet | == Soviet ferris wheel == | ||
The soviet-ferris-wheel temperament may be described as 320 & 460. It was named by [[Eliora]] in 2022 because it has a period of 1/20 octave, and there are 20 cabins on a standard ferris wheel found throughout most of Eastern Europe and Central Asia (as in abandoned Pripyat wheel, for example). | |||
The 5-limit comma is an interval which can also be produced by closing twenty [[375/256]]'s at 11 octaves, tempering this interval to 11\20. | |||
[[Subgroup]]: 2.3.5.7 | |||
[[Comma list]]: 65625/65536, 1977326743/1968300000 | |||
{{Mapping|legend=1| 20 0 57 35 | 0 3 -1 2 }} | |||
: mapping generators: ~16807/16200, ~3456/2401 | |||
[[Optimal tuning]]s: | |||
* [[WE]]: ~16807/16200 = 60.0061{{c}}, ~3456/2401 = 634.0252{{c}} | |||
: [[error map]]: {{val| +0.121 +0.121 +0.007 -0.563 }} | |||
* [[CWE]]: ~16807/16200 = 60.0000{{c}}, ~3456/2401 = 633.9770{{c}} | |||
: error map: {{val| 0.000 -0.024 -0.291 -0.872 }} | |||
{{Optimal ET sequence|legend=1| 140, 320, 460, 600, 1060d }} | |||
[[Badness]] (Sintel): 5.25 | |||
=== 11-limit === | === 11-limit === | ||
Subgroup: 2.3.5.7.11 | Subgroup: 2.3.5.7.11 | ||
Comma list: 9801/9800, 65625/65536, 422576/421875 | Comma list: 9801/9800, 65625/65536, 422576/421875 | ||
{{Mapping|legend=0| 20 0 57 35 122 | 0 3 -1 2 5 }} | |||
Optimal tunings: | |||
* WE: ~512/495 = 60.0085{{c}}, ~231/160 = 633.9990{{c}} | |||
* CWE: ~512/495 = 60.0000{{c}}, ~231/160 = 633.9127{{c}} | |||
Optimal | {{Optimal ET sequence|legend=0| 140, 320, 460 }} | ||
Badness (Sintel): 2.92 | |||
=== 13-limit === | === 13-limit === | ||
| Line 53: | Line 51: | ||
Comma list: 1001/1000, 4225/4224, 4459/4455, 86625/86528 | Comma list: 1001/1000, 4225/4224, 4459/4455, 86625/86528 | ||
{{Mapping|legend=0| 20 0 57 35 122 74 | 0 3 -1 2 5 0 }} | |||
Optimal tunings: | |||
* WE: ~512/495 = 60.0082{{c}}, ~75/52 = 633.9971{{c}} | |||
* CWE: ~512/495 = 60.0000{{c}}, ~75/52 = 633.9127{{c}} | |||
Optimal | {{Optimal ET sequence|legend=0| 140, 320, 460 }} | ||
===17-limit=== | Badness (Sintel): 1.48 | ||
=== 17-limit === | |||
Subgroup: 2.3.5.7.11.13.17 | Subgroup: 2.3.5.7.11.13.17 | ||
Comma list: 833/832, 1001/1000, 1225/1224, 4225/4224, 4459/4455 | Comma list: 833/832, 1001/1000, 1225/1224, 4225/4224, 4459/4455 | ||
{{Mapping|legend=0| 20 0 57 35 122 74 124 | 0 3 -1 2 5 0 -4 }} | |||
Optimal tunings: | |||
* WE: ~88/85 = 60.0081{{c}}, ~75/52 = 633.9982{{c}} | |||
* CWE: ~88/85 = 60.0000{{c}}, ~75/52 = 633.9117{{c}} | |||
Optimal | {{Optimal ET sequence|legend=0| 140, 320, 460 }} | ||
Badness (Sintel): 1.14 | |||
===19-limit=== | |||
=== 19-limit === | |||
Subgroup: 2.3.5.7.11.13.17.19 | Subgroup: 2.3.5.7.11.13.17.19 | ||
Comma list: 833/832, 1001/1000, 1225/1224, 1729/1728, 2926/2925, 4459/4455 | Comma list: 833/832, 1001/1000, 1225/1224, 1729/1728, 2926/2925, 4459/4455 | ||
{{Mapping|legend=0| 20 0 57 35 122 74 124 11 | 0 3 -1 2 5 0 -4 7 }} | |||
Optimal tunings: | |||
* WE: ~88/85 = 60.0075{{c}}, ~75/52 = 633.9713{{c}} | |||
* CWE: ~88/85 = 60.0000{{c}}, ~75/52 = 633.8948{{c}} | |||
Optimal | {{Optimal ET sequence|legend=0| 140, 320, 460 }} | ||
Badness (Sintel): 1.16 | |||
==Calcium== | == Calcium == | ||
Calcium is a highly precise and high-limit temperament, described as 2000 & 2460. [[2000edo]] and [[2460edo]] are adjacent members of a sequence of tunings with progressively less error in 19-limit. In this temperament, some of the simpler intervals are [[5/3]] and [[17/13]], reached in two generator steps, as well as [[11/7]] and [[19/16]], reached in eight generator steps. | |||
Calcium was named by [[Eliora]] in 2022 after the 20th element, following the convention of naming some fractional-octave temperaments after chemical elements. | |||
=== 17-limit === | === 17-limit === | ||
Subgroup: 2.3.5.7.11.13.17 | |||
Comma list: 9801/9800, 10648/10647, 12376/12375, 37180/37179, 903168/903125 | |||
{{Mapping|legend=0| 20 3 12 -73 -37 8 10 | 0 10 12 45 37 23 25 }} | |||
: mapping generators: ~88/85, ~243/220 | |||
Optimal tunings: | |||
* WE: ~88/85 = 59.9999{{c}}, ~243/220 = 172.1964{{c}} | |||
* CWE: ~88/85 = 60.0000{{c}}, ~243/220 = 172.1966{{c}} | |||
{{Optimal ET sequence|legend=0| 460, 1540d, 2000, 2460, 4460, 6920 }} | |||
Badness (Sintel): 0.909 | |||
=== 19-limit === | === 19-limit === | ||
Subgroup: 2.3.5.7.11.13.17.19 | Subgroup: 2.3.5.7.11.13.17.19 | ||
Comma list: 9801/9800, 12376/12375, 89376/89375, 104976/104975 | Comma list: 9801/9800, 10648/10647, 12376/12375, 89376/89375, 104976/104975, 1549184/1549125 | ||
{{Mapping|legend=0| 20 3 12 -73 -37 8 10 62 | 0 10 12 45 37 23 25 8 }} | |||
: mapping generators: ~88/85, ~169/153 | |||
Optimal tunings: | |||
* WE: ~88/85 = 59.9997{{c}}, ~169/153 = 172.1962{{c}} | |||
* CWE: ~88/85 = 60.0000{{c}}, ~169/153 = 172.1969{{c}} | |||
Optimal | {{Optimal ET sequence|legend=1| 460, 1540d, 2000, 2460, 4460, 11380h }} | ||
Badness (Sintel): 0.765 | |||
===23-limit=== | === 23-limit === | ||
Subgroup: 2.3.5.7.11.13.17.19.23 | Subgroup: 2.3.5.7.11.13.17.19.23 | ||
Comma list: 9801/9800, 10626/10625, 12376/12375, 21505/21504, 21736/21735, 89376/89375 | Comma list: 9801/9800, 10626/10625, 10648/10647, 12376/12375, 21505/21504, 21736/21735, 89376/89375 | ||
{{Mapping|legend=0| 20 3 12 -73 -37 8 10 62 145 | 0 10 12 45 37 23 25 8 -19 }} | |||
Optimal tunings: | |||
* WE: ~88/85 = 59.9999{{c}}, ~169/153 = 172.1963{{c}} | |||
* CWE: ~88/85 = 60.0000{{c}}, ~169/153 = 172.1966{{c}} | |||
{{Optimal ET sequence|legend=0| 460, 2000, 2460, 4460, 6920 }} | |||
Badness (Sintel): 0.839 | |||
{{Navbox fractional-octave}} | {{Navbox fractional-octave}} | ||
[[Category:20edo]] | [[Category:20edo]] | ||