136/135: Difference between revisions

Temperaments: srutal archagall can be singled out
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{{Infobox Interval
{{Infobox Interval
| Name = diatisma, fiventeen comma
| Name = diatisma, diatic comma, fiventeen comma
| Color name = 17og2, Sogu 2nd, <br>Sogu comma
| Color name = 17og2, Sogu 2nd, <br>Sogu comma
| Comma = yes
| Comma = yes
}}
}}
'''136/135''', the ''diatisma'' or ''fiventeen comma'', is a [[17-limit]] [[small comma]]. It is equal to ([[32/27]])/([[20/17]]) and therefore ([[51/40]])/([[81/64]]). It is also [[1/2-square-particular|trivially]] the difference between between [[16/15]] and [[18/17]] and therefore the difference between [[17/16]] * [[16/15]] = [[17/15]] and [[18/17]] * [[17/16]] = [[9/8]] (as the two 17/16's cancel).
'''136/135''', the '''diatisma''', '''diatic comma''' or '''fiventeen comma''', is a [[17-limit]] [[small comma]]. It is the interval that separates [[17/10]] and [[27/16]] (or their octave complements [[20/17]] and [[32/27]]) and that separates [[30/17]] and [[16/9]] (or their octave complements [[17/15]] and [[9/8]]). It is also the difference between [[16/15]] and [[18/17]] with an [[S-expression]] of [[256/255|S16]] × [[289/288|S17]] or ((16/15)(17/16))/((17/16)(18/17)).  


== Temperaments ==
== Temperaments ==
=== Fiventeen ===
=== Fiventeen ===
[[17edo]] makes a good tuning (especially for its size) for the 2.3.17/5-subgroup {136/135} rank 2 temperament which implies a [[supersoft]] [[pentic]] pentad of 30:34:40:45:51:60 (because as aforementioned [[17/15]] is equated with [[9/8]]) although [[80edo]] might be preferred for a more accurate [[51/40]] and it and [[46edo]] might be preferred for more accurate fifths. The same is true of the related rank 3 temperament diatic, described below.
[[17edo]] makes a good tuning (especially for its size) for the 2.3.17/5-subgroup {136/135} rank 2 temperament which implies a [[supersoft]] [[pentic]] pentad of [[~]]30:34:40:45:51:60 (because as aforementioned [[17/15]] is equated with [[9/8]]), corresponding approximately to a just [[20/17]] tuning, although [[80edo]] might be preferred for an approximately just [[51/40]] to optimize plausibility slightly more, and 80 + 17 = [[97edo]] and 97 + 17 = [[114edo]] do even better in striking a balance between 80edo's more stable tuning and that having 20/17 more accurate (as in 17edo) is useful because of the more convincing suggestion of the two 15:17:20 chords present in the fiventeen pentad. The same is true of the related rank-3 temperament diatic, described below, for which the [[optimal ET sequence]] is much more characteristic of optimized tunings, finding [[34edo]], then [[80edo]], then 34 + 80 = [[114edo]] and amazingly even 114 + 80 = [[194edo|194bc-edo]], though because of its focus on primes 5 and 17 it misses 97edo as a tuning, and slightly less optimized though still interesting [[63edo]] and 63 + 80 = [[143edo]] tunings are found in the optimal ET sequence for fiventeen.


[[Subgroup]]: 2.3.17/5
[[Subgroup]]: 2.3.17/5
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: sval mapping generators: ~2, ~3
: sval mapping generators: ~2, ~3


[[Optimal tuning]] ([[Tp tuning|subgroup CTE]]): ~2 = 1\1, ~3/2 = 704.1088
[[Optimal tuning]]s:
* [[Tp tuning|subgroup]] [[CEE]]: 2 = 1\1, ~3/2 = 705.440
* [[Tp tuning|subgroup]] [[CTE]]: ~2 = 1\1, ~3/2 = 704.1088


{{Optimal ET sequence|legend=1| 5, 12, 17, 46, 63, 143 }}
{{Optimal ET sequence|legend=1| 5, 12, 17, 46, 63, 143 }}
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: sval mapping generators: ~2, ~3, ~5
: sval mapping generators: ~2, ~3, ~5


[[Optimal tuning]] ([[Tp tuning|subgroup CTE]]): ~2 = 1\1, ~3/2 = 704.1088, ~5/4 = 387.8544
[[Optimal tuning]] ([[Tp tuning|subgroup]] [[CTE]]): ~2 = 1\1, ~3/2 = 704.1088, ~5/4 = 387.8544


{{Optimal ET sequence|legend=1| 10, 12, 22, 34, 80, 114, 194bc }}
{{Optimal ET sequence|legend=1| 10, 12, 22, 34, 80, 114, 194bc }}
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: sval mapping generators: ~2, ~3, ~5, ~7, ~11, ~13
: sval mapping generators: ~2, ~3, ~5, ~7, ~11, ~13


[[Optimal tuning]] ([[Tp tuning|subgroup CTE]]): ~2 = 1\1, ~3/2 = 704.1088, ~5/4 = 387.8544, ~7/4, ~11/8, ~13/8
[[Optimal tuning]] ([[Tp tuning|subgroup]] [[CTE]]): ~2 = 1\1, ~3/2 = 704.1088, ~5/4 = 387.8544, ~7/4, ~11/8, ~13/8


{{Optimal ET sequence|legend=1| 22, 27eg, 29g, 34d, 39dfg, 41g, 46, 58, 80, 104c, 114e, 126(f), 136ef, 148d, 167g, 216bdef }}*
{{Optimal ET sequence|legend=1| 22, 27eg, 29g, 34d, 39dfg, 41g, 46, 58, 80, 104c, 114e, 126(f), 136ef, 148d, 167g, 216bdef }}*
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* [[Small comma]]
* [[Small comma]]
* [[List of superparticular intervals]]
* [[List of superparticular intervals]]
[[Category:Commas with unknown etymology]]
{{todo|improve readability|inline=1|comment=Rewrite the etymology section to be easier to parse and less vague.}}