7L 4s: Difference between revisions

ArrowHead294 (talk | contribs)
mNo edit summary
CompactStar (talk | contribs)
 
(3 intermediate revisions by 2 users not shown)
Line 4: Line 4:
7L 4s fails to represent common just intonation intervals and simple temperaments, and it has no clearly discernible harmonic entropy minimum. From a purely computational perspective, 7L 4s's harmonic entropy minimum is [[improper]] and is associated with unusually large step ratios.
7L 4s fails to represent common just intonation intervals and simple temperaments, and it has no clearly discernible harmonic entropy minimum. From a purely computational perspective, 7L 4s's harmonic entropy minimum is [[improper]] and is associated with unusually large step ratios.


Near the harmonic entropy minimum, the simplest temperament of low-complexity JI supported by 7L 4s is [[amity]] and its variant [[hitchcock]]. It is unconventional to put forward this as the most common approach to this scale, because the large and steps are extremely unequal, being at least of 5:1 step ratio in [[39edo]], the smallest patent val supporting either of the two. However, it is still significant by virtue of it being the only [[5-limit]] [[temperament]] representation of 7L 4s with reasonably low badness.  
Near the harmonic entropy minimum, the simplest temperament of low-complexity JI supported by 7L 4s is [[amity]] and its variant [[hitchcock]]. It is unconventional to put forward this as the most common approach to this scale, because amity's mapping of [[5/4]] is reached by -13 generators and is thus inaccessible, and because the large and steps are extremely unequal, being at least of 5:1 step ratio in [[39edo]], the smallest patent val supporting either of the two. However, it is still significant by virtue of it being the only [[5-limit]] [[temperament]] representation of 7L 4s with reasonably low badness.  


A temperament which spans more of the tuning range is [[sixix]], but it is high in just intonation error relative to its step sizes. Additionally, as sixix shares the mapping for [[3/2]] with amity (-5 generators), the generator is of a similar size, and the most accurate tunings of sixix, [[32edo]] and [[39edo|39c-edo]], have highly improper 7L 4s scales like with amity.
A temperament which spans more of the tuning range is [[sixix]], but it is high in just intonation error relative to its step sizes. Additionally, as sixix shares the mapping for [[3/2]] with amity (-5 generators), the generator is of a similar size, and the most accurate tunings of sixix, [[32edo]] and [[39edo|39c-edo]], have highly improper 7L 4s scales like with amity.
Line 16: Line 16:
In the equal divisions which are in the size of hundreds, [[cohemimabila]] temperament is the first intepretation of 7L 4s of reasonable hardness (roughly semihard) through regular temperament theory. It is supported by [[43edo]], notable for being studied by {{w|Joseph Sauveur}} due to harmonic strength, and [[111edo]], which is uniquely consistent in the 15-odd-limit. The generator is mapped to [[128/105]], and in higher limits it is tempered together with 17/14.  
In the equal divisions which are in the size of hundreds, [[cohemimabila]] temperament is the first intepretation of 7L 4s of reasonable hardness (roughly semihard) through regular temperament theory. It is supported by [[43edo]], notable for being studied by {{w|Joseph Sauveur}} due to harmonic strength, and [[111edo]], which is uniquely consistent in the 15-odd-limit. The generator is mapped to [[128/105]], and in higher limits it is tempered together with 17/14.  


The scale can be made by using every other generator of the [[tertiaschis]] temperament, for example in [[159edo]], which is realized as 2.9.5.7.33.13.17 subgroup {{nowrap|47 & 112}} temperament, where it tempers out exactly the same commas as tertiaschis.
The scale can be made by using every other generator of the [[tertiaschis]] temperament, for example in [[159edo]], which is realized as 2.9.5.7.33.13.17 subgroup [[daemotertiaschis]] ({{nowrap|47 & 112}}) temperament, where it tempers out exactly the same commas as tertiaschis.


== Nomenclature ==
== Nomenclature ==
Line 41: Line 41:
| 6/5 = [[Mabon]]  
| 6/5 = [[Mabon]]  
| 7/5 = [[Rarity]]  
| 7/5 = [[Rarity]]  
| 3/2 = [[Demon]]
| 13/8 = Unnamed golden tuning  
| 13/8 = Unnamed golden tuning  
| 13/5 = [[Cohemimabila]], unnamed golden tuning  
| 13/5 = [[Cohemimabila]], unnamed golden tuning