Mothra: Difference between revisions
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| Mapping = 1; 3 12 -1 | | Mapping = 1; 3 12 -1 | ||
| Pergen = (P8, P5/3) | | Pergen = (P8, P5/3) | ||
| Odd limit 1 = 7 | Mistuning 1 = | | Odd limit 1 = 7 | Mistuning 1 = 5.4 | Complexity 1 = 31 | ||
| Odd limit 2 = (2.3.5.7) 21 | Mistuning 2 = | | Odd limit 2 = (2.3.5.7) 21 | Mistuning 2 = 10.8 | Complexity 2 = 36 | ||
}} | }} | ||
'''Mothra''' is a temperament | '''Mothra''', also known as '''cynder''', is a temperament of the [[7-limit]] that is a strong extension to [[slendric]], which is defined by splitting a perfect fifth representing [[3/2]] into three intervals of [[8/7]], tempering out [[1029/1024]]. The fifth of mothra is flattened to a [[meantone]] fifth, so that it reaches [[5/4]] when stacked four times and [[81/80]] is tempered out, unlike that of the other slendric extension [[rodan]], which is sharpened from just. This has the effect of bringing the generator 8/7 considerably closer to just, and also allowing [[MOS scale]]s of mothra to be more melodically usable than those of other forms of slendric, as the structurally-pervasive small step known as the [[quark]] (the residue between the octave and 5 generators, representing [[49/48]], [[64/63]], and in mothra also [[36/35]]) is larger here. [[EDOs]] that support mothra include [[26edo]], [[31edo]], and [[36edo]], and 31 is a particularly good tuning. | ||
In the [[11-limit]], two extensions are of note: undecimal mothra (26 & 31), which tempers out [[99/98]], [[385/384]] and [[441/440]] to find the 11th harmonic at 8 generators down, and mosura (31 & 36), which tempers out [[176/175]] to find the 11th harmonic at 23 generators up. These two mappings merge at 31edo, which is therefore a uniquely suitable tuning for 11-limit mothra. | In the [[11-limit]], two extensions are of note: undecimal mothra (26 & 31), which tempers out [[99/98]], [[385/384]] and [[441/440]] to find the 11th harmonic at 8 generators down, and mosura (31 & 36), which tempers out [[176/175]] to find the 11th harmonic at 23 generators up. These two mappings merge at 31edo, which is therefore a uniquely suitable tuning for 11-limit mothra. | ||
In higher limits, one may note that the two-generator interval closely approximates [[17/13]], and that the six-generator interval - the meantone whole tone of [[9/8]][[~]][[10/9]], approximates [[19/17]] | In higher limits, one may note that the two-generator interval closely approximates [[17/13]], and that the six-generator interval - the meantone whole tone of [[9/8]][[~]][[10/9]], approximates [[19/17]] - so that the 13:17:19 chord is well-represented; it is worth noting also that this chord is entirely included within the subtemperament obtained from taking every other generator of mothra, which is [[A-team]] (the crawma, [[83521/83486]], is the relevant comma tempered out here). This can be combined with the canonical mapping of 13 for each undecimal extension, which tempers out [[144/143]], to provide a natural route to the [[19-limit]]. | ||
For technical data, see [[Gamelismic clan #Mothra]]. | For technical data, see [[Gamelismic clan #Mothra]]. | ||
== Intervals == | == Intervals == | ||
As a strong extension of slendric, mothra's intervals can be expressed using the same system of extended diatonic interval naming [[Slendric#Interval categories|used for slendric]]. It is particularly convenient to use diatonic conventions for mothra, because its chain of fifths is meantone, and therefore 5/4 is simply read as a major third. | As a strong extension of slendric, mothra's intervals can be expressed using the same system of extended diatonic interval naming [[Slendric #Interval categories|used for slendric]]. It is particularly convenient to use diatonic conventions for mothra, because its chain of fifths is meantone, and therefore 5/4 is simply read as a major third. | ||
In the following table, odd harmonics and subharmonics 1–21 are labeled in '''bold'''. | In the following table, odd harmonics and subharmonics 1–21 are labeled in '''bold'''. | ||
{| class="wikitable sortable center- | {| class="wikitable sortable center-1 center-2 right-3" | ||
|- | |- | ||
! rowspan="3" | | ! rowspan="3" | # !! rowspan="3" | Extended <br> diatonic <br> interval !! rowspan="3" | Cents* !! colspan="3" | Approximate ratios | ||
|- | |- | ||
! rowspan="2" | 7-limit intervals !! colspan="2" | Intervals of | ! rowspan="2" | 7-limit intervals !! colspan="2" | Intervals of 11-limit extensions | ||
|- | |- | ||
! Undecimal mothra !! Mosura | ! Undecimal mothra !! Mosura | ||
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| 33/32, 55/54 | | 33/32, 55/54 | ||
|} | |} | ||
<nowiki/>* In 7-limit [[CWE tuning]] | <nowiki/>* In 7-limit [[CWE tuning]], octave reduced | ||
== Tuning spectrum == | == Tuning spectrum == | ||
{{see also|Slendric #Tuning spectrum}} | |||
Vals refer to the appropriate undecimal extension in the EDO's range. | Vals refer to the appropriate undecimal extension in the EDO's range. | ||
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| 232.193 | | 232.193 | ||
| | | | ||
| 1/4-comma meantone fifth, 5-odd-limit minimax | | 1/4-comma meantone fifth, (7-limit) 5- through 21-odd-limit minimax | ||
|- | |- | ||
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