243/242: Difference between revisions

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Tempering it out in the full 11-limit leads to the rastmic temperament, enabling [[rastmic chords]], or, in the 2.3.11 subgroup, the [[Subgroup temperaments #Neutral|neutral]] temperament, enabling [[Neutral tetrad|neutral chords]].
Tempering it out in the full 11-limit leads to the rastmic temperament, enabling [[rastmic chords]], or, in the 2.3.11 subgroup, the [[Subgroup temperaments #Neutral|neutral]] temperament, enabling [[Neutral tetrad|neutral chords]].


=== Rastmic temperament ===
=== Rastmic ===
 
Subgroup: 2.3.5.7.11
Subgroup: 2.3.5.7.11


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[[Mapping]]: [{{val| 1 1 0 0 2 }}, {{val| 0 2 0 0 5 }}, {{val| 0 0 1 0 0 }}, {{val| 0 0 0 1 0}}]
[[Mapping]]: [{{val| 1 1 0 0 2 }}, {{val| 0 2 0 0 5 }}, {{val| 0 0 1 0 0 }}, {{val| 0 0 0 1 0}}]


[[POTE generator]]s: ~11/9 = 350.5254, ~5/4 = 386.1653, ~7/4 = 968.6464
[[POTE tuning]]: ~11/9 = 350.5254, ~5/4 = 386.1653, ~7/4 = 968.6464


{{Val list|legend=1| 7d, 10, 14c, 17c, 24, 27e, 31, 41, 58, 72, 130, 202 }}
{{Val list|legend=1| 7d, 10, 14c, 17c, 24, 27e, 31, 41, 58, 72, 130, 202 }}
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[[Badness]]: 0.05088 × 10<sup>-6</sup>
[[Badness]]: 0.05088 × 10<sup>-6</sup>


=== Neutral temperament ===
=== Neutral ===
 
Subgroup: 2.3.11  
Subgroup: 2.3.11  


[[Comma list]]: 243/242
[[Comma list]]: 243/242


[[Lp_tuning|POL2 generator]]: ~11/9 = 350.525
[[Sval]] [[mapping]]: [{{val| 1 1 2 }}, {{val| 0 2 5 }}]
 
[[Gencom]] [[mapping]]: [{{val| 1 1 0 0 2 }}, {{val| 0 2 0 0 5 }}]


Gencom: [2 11/9; 243/242]
Gencom: [2 11/9; 243/242]


Gencom mapping: [&lt;1 1 0 0 2|, &lt;0 2 0 0 5|]
[[POTE tuning]]: ~11/9 = 350.525
 
Map: [&lt;1 1 2|, &lt;0 2 5|]


EDOs: 7, 10, 17, 24, 41, 65, 89, 202, 291, 380
{{Val list|legend=1| 7, 10, 17, 24, 65, 89, 202, 291, 380 }}


[[Tp_tuning#T2 tuning|RMS error]]: 0.3021 cents
[[Tp tuning #T2 tuning|RMS error]]: 0.3021 cents


== See also ==
== See also ==
* [[Rank-4 temperament]]
* [[Rastmic temperaments]], a collection of rank-3 temperaments where it is tempered out
* [[Rastmic temperaments]], a collection of rank-3 temperaments where it is tempered out
* [[Rastmic chords]]
* [[Rastmic chords]]

Revision as of 13:45, 6 October 2021

Interval information
Ratio 243/242
Factorization 2-1 × 35 × 11-2
Monzo [-1 5 0 0 -2
Size in cents 7.13912¢
Names rastma,
neutral third comma
FJS name [math]\displaystyle{ \text{A1}_{121} }[/math]
Special properties superparticular,
reduced
Tenney height (log2 nd) 15.8437
Weil height (log2 max(n, d)) 15.8496
Wilson height (sopfr(nd)) 39
Open this interval in xen-calc

243/242, the rastma or the neutral third comma, is an 11-limit (also 2.3.11 subgroup) comma with a value of roughly 7.1 cents. It is significant in Just Intonation as the amount by which a stack of two 11/9 neutral thirds fall short of 3/2 just perfect fifth, by which a stack of two 33/32 quartertones falls short of an apotome (2187/2048) as well as the difference between 11/9 and 27/22, and, the difference between 45/44 and 55/54. The last makes the theory where the rastma serves as the subchroma that separates greater and lesser 11-limit chromas – a theory that becomes especially useful when one works extensively with high-fidelity renditions of the 11-limit.

Temperaments

Tempering it out in the full 11-limit leads to the rastmic temperament, enabling rastmic chords, or, in the 2.3.11 subgroup, the neutral temperament, enabling neutral chords.

Rastmic

Subgroup: 2.3.5.7.11

Comma list: 243/242

Mapping: [1 1 0 0 2], 0 2 0 0 5], 0 0 1 0 0], 0 0 0 1 0]]

POTE tuning: ~11/9 = 350.5254, ~5/4 = 386.1653, ~7/4 = 968.6464

Template:Val list

Badness: 0.05088 × 10-6

Neutral

Subgroup: 2.3.11

Comma list: 243/242

Sval mapping: [1 1 2], 0 2 5]]

Gencom mapping: [1 1 0 0 2], 0 2 0 0 5]]

Gencom: [2 11/9; 243/242]

POTE tuning: ~11/9 = 350.525

Template:Val list

RMS error: 0.3021 cents

See also