No-twos subgroup temperaments: Difference between revisions
Merge from antares |
Merge from electra |
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Classified by focusing on the mapping of 5th harmonic, similar to [[Rank-2 temperaments by mapping of 3]]. | Classified by focusing on the mapping of 5th harmonic, similar to [[Rank-2 temperaments by mapping of 3]]. | ||
* Arcturus, antares aldebaran and polaris have a 3/1 period and ~5/3 generator. There is one-to-one correspondence between the 3.5 subgroup and mapped intervals. | * Arcturus, antares, aldebaran and polaris have a 3/1 period and ~5/3 generator. There is one-to-one correspondence between the 3.5 subgroup and mapped intervals. | ||
* BPS has a ~9/7 generator, two of which give the ~5/3. | * BPS has a ~9/7 generator, two of which give the ~5/3. | ||
* Sirius has a ~25/21 generator, three of which give the ~5/3. | * Sirius has a ~25/21 generator, three of which give the ~5/3. | ||
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By splitting the generator of sirius into three, remus efficiently represents the no-2's 13-limit with [[mos scale]]s of 18, 25, 32, or 39 steps. | By splitting the generator of sirius into three, remus efficiently represents the no-2's 13-limit with [[mos scale]]s of 18, 25, 32, or 39 steps. | ||
This is essentially [[electra]] but with prime 7, or more accurately, electra is the no-7's [[restriction]] of this temperament. | This is essentially [[#Electra|electra]] but with prime 7, or more accurately, electra is the no-7's [[restriction]] of this temperament. | ||
Subgroup: 3.5.7.11 | Subgroup: 3.5.7.11 | ||
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Badness (Sintel): 0.838 | Badness (Sintel): 0.838 | ||
== Electra == | |||
[[File:Electra chords.wav|thumb|Just 11:13:15 and 143:165:195 triads on A]] | |||
Electra tempers out [[1875/1859]] and [[14641/14625]] in the 3.5.11.13 subgroup, with a generator near [[15/11]] or its tritave complement, [[11/5]]. It possesses [[mos scale]]s of the families {{mos scalesig|link=1|4L 3s<3/1>}}, {{mos scalesig|link=1|7L 4s<3/1>}}, and {{mos scalesig|link=1|7L 11s<3/1>}}. | |||
The 11:13:15 triad is a characteristic feature of many electra scales, and has been suggeested by {{u|CompactStar}} as a fundamental sonority for no-2's music, due to being relatively consonant compared to other no-2's chords. There is also a "minor" version of this triad, 143:165:195. If 11:13:15 is treated as the fundamental sonority of no-2's music, then electra can be viewed as the analogue to [[meantone family #Meantone|meantone]]. | |||
The name was given by CompactStar in 2023 after the star {{w|Electra (star)|Electra}}, following a series of non-octave temperaments that were named after stars. | |||
[[Subgroup]]: 3.5.11 | |||
[[Comma list]]: 2373046875/2357947691 | |||
{{Mapping|legend=3| 1 -5 -5 | 0 9 10 }} | |||
: mapping generators: ~3, ~11/5 | |||
[[Optimal tuning]]s: | |||
* [[WE]]: ~3 = 1901.8666{{c}}, ~11/5 = 1366.1408{{c}} | |||
: [[error map]]: {{val| -0.088 -0.379 +0.757 }} | |||
* [[CWE]]: ~3 = 1901.9550{{c}}, ~11/5 = 1366.1964{{c}} | |||
: error map: {{val| 0.000 -0.321 +0.8712 }} | |||
[[Optimal ET sequence]]: [[32edt|b32]], [[39edt|b39]], [[71edt|b71]], [[1239edt|b1239e]], [[1310edt|b1310e]], …, [[1665edt|b1665e]], [[1736edt|b1736e]] | |||
[[Badness]] (Sintel): 0.656 | |||
=== 3.5.11.13 subgroup === | |||
Subgroup: 3.5.11.13 | |||
Comma list: 1875/1859, 14641/14625 | |||
{{Mapping|legend=2| 1 -5 -5 -7 | 0 9 10 13 }} | |||
Optimal tunings: | |||
* WE: ~3 = 1901.8899{{c}}, ~11/5 = 1365.9871{{c}} | |||
* CWE: ~3 = 1901.9550{{c}}, ~11/5 = 1366.0281{{c}} | |||
Optimal ET sequence: [[32edt|b32]], [[39edt|b39]], [[71edt|b71]], [[110edt|b110]], [[181edt|b181]] | |||
Badness (Sintel): 0.405 | |||
; Scales | |||
* [[Electra7]] | |||
== Alnilam == | == Alnilam == | ||