Subgroup temperaments: Difference between revisions

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== 2.3.… subgroups ==
== 2.3.… subgroups ==
=== Shrub ===
=== Shrub ===
Named by [[User: VectorGraphics|Vector]] in 2026, shrub is a [[restriction]] of [[diaschismic family #Diaschismic|diaschismic]] which omits the tritone to produce a [[5L 2s|diatonic]] scale. True to its name, it generates a [[neogothic major and minor|shrubmajor]]{{idio}} third (~425{{c}}) in quarter-comma tuning. It has an equal-temperament join of 12 & 17.  
Named by [[User: VectorGraphics|Vector]] in 2026, shrub is a [[restriction]] of [[diaschismic family #Diaschismic|diaschismic]] which omits the tritone to produce a [[5L 2s|diatonic]] scale. True to its name, it generates a [[neogothic major and minor|shrubmajor]]{{idio}} third (~425{{c}}) in quarter-comma tuning. Specifically, the diatonic major third in shrub temperament is [[32/25]]. It has an equal-temperament join of 12 & 17.
 
It can also admit a [[41/1|41st harmonic]] by tempering out [[82/81]] (same mapping as [[reversed meantone]]). However, its tuning tends to be flat, and with the rest of the harmonics tending sharp, this will increase the overall error.  
It can also admit a [[41/1|41st harmonic]] by tempering out [[82/81]] (same mapping as [[reversed meantone]]). However, its tuning tends to be flat, and with the rest of the harmonics tending sharp, this will increase the overall error.  


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=== Barbados ===
=== Barbados ===
Barbados is the restriction of [[#Bridgetown|bridgetown]] to the 2.3.13/5 subgroup, and tempers out [[676/675]] alone. The [[minimax tuning]] for this makes the generator the cube root of 20/13, or 248.5953 cents. Edos which may be used for it are [[24edo]], [[29edo]], [[53edo]] and [[111edo]], with [[mos scale]]s of size 5, 9, 14, 19, 24 and 29 making for a good variety of scales. If tuned near-optimally, it is just barely a [[microtemperament]], with errors of under one cent for 3 and 13/5, and given its ultra-low complexity, this makes Barbados an extremely low-[[badness]] temperament within its subgroup.
Barbados tempers out [[676/675]] alone in the 2.3.13/5 subgroup. It melodically resembles [[semaphoresmic clan #Semaphore|semaphore]], but targets specifically the interseptimal intervals like [[13/10]] and [[15/13]]. [[#Bridgetown|Bridgetown]], which adds 11/5, is a notable extension of it.  
 
The {1, 3, 13/5} and {1, 3, 9, 13/5} [[minimax tuning]]s have 13/5 and 3 tuned pure, respectively. Edos which may be used for it include but are not limited to [[24edo]], [[29edo]], and [[53edo]], with [[mos scale]]s of size 5, 9, 14, 19, 24 and 29 making for a good variety of scales. If tuned near-optimally, it is just barely a [[microtemperament]], with errors of under one cent for 3 and 13/5, and given its ultra-low complexity, this makes barbados an extremely [[badness|low-badness]] temperament within its subgroup.


Several related temperaments, all tempering out 676/675, can be found in [[The Archipelago]].
Several related temperaments, all tempering out 676/675, can be found in [[The Archipelago]].
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[[Optimal tuning]]s:  
[[Optimal tuning]]s:  
* [[Tp tuning|Subgroup]] [[WE]]: ~2 = 1199.9502{{c}}, ~26/15 = 951.0713{{c}}
* [[Tp tuning|Subgroup]] [[WE]]: ~2 = 1199.9502{{c}}, ~26/15 = 951.0713{{c}}
: [[error map]]: {{val| -0.050 +0.188 -0.950 }}
* [[Tp tuning|Subgroup]] [[CWE]]: ~2 = 1200.0000{{c}}, ~26/15 = 951.0933{{c}}
* [[Tp tuning|Subgroup]] [[CWE]]: ~2 = 1200.0000{{c}}, ~26/15 = 951.0933{{c}}
: error map: {{val| 0.000 +0.232 -0.934 }}


{{Optimal ET sequence|legend=1| 5, 14, 19, 24, 29, 53, 82, 135 }}
{{Optimal ET sequence|legend=1| 5, 14, 19, 24, 29, 53, 82, 135 }}


[[Badness]] (Smith): 0.002335
[[Badness]] (Sintel): 0.022


; Music
; Music
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=== Demon ===
=== Demon ===
Demon is a 2.9.11 subgroup temperament which equates three [[11/9]]'s with [[16/9]], or equivalently three [[18/11]]'s with [[9/8]], tempering out [[1331/1296]]. This results in [[11/9]] being tuned flat to a supraminor third. It was discovered by {{u|CompactStar}} while searching for temperaments assosciated with the [[7L 4s]] ("daemotonic") [[mos]], known for its lack of representation of simple temperaments. The optimal tuning for the demon temperament is near the basic tuning of 7L 4s (13\18), and indeed [[18edo]] supports this temperament. It is technically a restriction of 11-limit [[porcupine]].
Demon is a 2.9.11 subgroup temperament which equates three [[11/9]]'s with [[16/9]], or equivalently three [[18/11]]'s with [[9/8]], tempering out [[1331/1296]]. This results in [[11/9]] being tuned flat to a supraminor third. It was discovered by {{u|CompactStar}} while searching for temperaments assosciated with the [[7L 4s]] ("daemotonic") [[mos]], known for its lack of representation of simple temperaments. The optimal tuning for the demon temperament is near the basic tuning of 7L 4s (13\18), and indeed [[18edo]] supports this temperament. It is technically a weak restriction of 11-limit [[porcupine]].


[[#Mabon|Mabon]] is a strong extension of this temperament to the 2.9.7.11 subgroup.  
[[#Mabon|Mabon]] is a strong extension of this temperament to the 2.9.7.11 subgroup.  
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== 5/2-repeating subgroups ==
== 5/2-repeating subgroups ==
=== Frosthog ===
=== Frosthog ===
Discovered and named by {{u|CompactStar}} in 2026, frosthog is a [[5/2]]-equivalent nonoctave temperament which tempers out the frostma, [[245/242]], in the 5/2.7/2.11/2 subgroup. Tempering out the frostma equates 2 11/7s to 5/2, thus the period is √(5/2) (which represents both [[11/7]] and [[35/22]]), while the generator is ~[[7/5]].  
Frosthog is a [[5/2]]-repeating non-octave temperament which tempers out the frostma, [[245/242]], in the 5/2.7/2.11/2 subgroup. Tempering out the frostma equates two [[11/7]]'s to 5/2, thus the period is sqrt(5/2) (which represents both 11/7 and [[35/22]]), while the generator is ~[[7/5]].  


It was formerly named ''permafrost'' but the name was changed to frosthog a day later due to a naming conflict with [[Pentacircle clan#Permafrost|another temperament]]. It is named after [[hedgehog]] and the frostma, as it is a "macro-hedgehog" temperament producing the same as MOS scales as hedgehog (compare [[macrodiatonic and microdiatonic scales]]).
It was discovered and named by {{u|CompactStar}} in 2026, after [[hedgehog]] and the frostma, as it is a "macro-hedgehog" temperament producing the same [[mos]] patterns as hedgehog (compare [[macrodiatonic and microdiatonic scales]]).


The 5/2.7/2.11/2 subgroup could be seen as a somewhat more practical version of the 5.7.11 subgroup (the essential "no-twos no-threes" subgroup) on account of both containing the 5:7:11 chord, and [[5/2]] being a much more workable period size than [[5/1]], although there is still the issue of how to make 5/2 sound equivalent.
The 5/2.7/2.11/2 subgroup could be seen as a somewhat more practical version of the 5.7.11 subgroup (the essential no-2's no-3's subgroup) on account of both containing the 5:7:11 chord, and [[5/2]] being a much more workable period size than [[5/1]], although there is still the issue of how to make 5/2 sound equivalent.


[[Subgroup]]: 5/2.7/2.11/2
[[Subgroup]]: 5/2.7/2.11/2


[[Comma list]]: 245/242 ({{monzo| 1 2 -2}})
[[Comma list]]: 245/242 ({{monzo| 1 2 -2 }})


{{Mapping|legend=3| 2 2 3| 0 1 1 }}
{{Mapping|legend=3| 2 0 1 | 0 1 1 }}
: mapping generators: ~11/7, ~7/5
: mapping generators: ~11/7, ~7/2


[[Optimal tuning]]s:  
[[Optimal tuning]]s:  
* [[Tp tuning|Subgroup]] [[WE]]: ~11/7 = 792.359{{c}}, ~7/5 = 579.931{{c}}
* [[Tp tuning|Subgroup]] [[WE]]: ~11/7 = 792.3594{{c}}, ~7/5 = 579.9314{{c}}
* [[Tp tuning|Subgroup]] [[CWE]]: ~11/7 = 793.157{{c}}, ~7/5 = 578.781{{c}}
* [[Tp tuning|Subgroup]] [[CWE]]: ~11/7 = 793.1569{{c}}, ~7/5 = 578.7807{{c}}


[[Optimal ET sequence]]: TBA
[[Optimal ET sequence]]: [[8ed5/2|*8]], [[14ed5/2|*14]], [[22ed5/2|*22]], [[30ed5/2|*30]], [[52ed5/2|*52]], [[82ed5/2|*82]]


[[Badness]] (Sintel): 0.060
[[Badness]] (Sintel): 0.060