225/224: Difference between revisions

Fredg999 category edits (talk | contribs)
Merge some see-also links to the temperament section; make a separate approximation section
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| Monzo = -5 2 2 -1
| Monzo = -5 2 2 -1
| Cents = 7.71152
| Cents = 7.71152
| Name = septimal kleisma, <br/> marvel comma
| Name = septimal kleisma, <br>marvel comma
| Color name = ryy-2, ruyoyo negative 2nd,<br> Ruyoyo comma
| Color name = ryy-2, ruyoyo negative 2nd,<br> Ruyoyo comma
| FJS name = d-2<sup>25</sup><sub>7</sub>
| FJS name = d-2<sup>25</sup><sub>7</sub>
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The interval of '''225/224''', the '''septimal kleisma''' or '''marvel comma''' is a [[7-limit]] [[superparticular]] ratio. It pops up as the difference between pairs of 7-limit ratios, for example as ([[15/14]])/([[16/15]]) or ([[45/32]])/([[7/5]]).
The interval of '''225/224''', the '''septimal kleisma''' or '''marvel comma''' is a [[7-limit]] [[superparticular]] ratio. It pops up as the difference between pairs of 7-limit ratios, for example as ([[15/14]])/([[16/15]]) or ([[45/32]])/([[7/5]]).
It is also the difference between [[81/80]] and [[126/125]] and is tempered out alongside these two commas in [[Meantone family#Septimal meantone|Septimal meantone]]. If we don't temper out this interval and instead repeatedly stack (and octave-reduce) it, we get [[311edo]], where it is equal to 2 steps, meaning 311edo is a circle of 225/224's. Note that this is not true for 226/225 or 224/223, the adjacent superparticulars, as they accumulate too much error to close into a circle in 311edo.
 
It is also the difference between [[81/80]] and [[126/125]] and is tempered out alongside these two commas in [[septimal meantone]]. In the 11-limit, it factors neatly into ([[385/384]])([[540/539]]).  


== Temperaments ==
== Temperaments ==
Tempering out this comma leads to the [[marvel family]] of temperaments, which enables [[marvel chords]].
Tempering out this comma leads to the [[marvel family]] of temperaments, which enables [[marvel chords]]. See [[marvel temperaments]] for a collection of rank-2 temperaments where it is tempered out.
 
== Approximation ==
If we do not temper out this interval and instead repeatedly stack (and octave-reduce) it, we get [[311edo]], where it is equal to 2 steps, meaning 311edo is a circle of 225/224's. Note that this is not true for 226/225 or 224/223, the adjacent superparticulars, as they accumulate too much error to close into a circle in 311edo.


== See also ==
== See also ==
* [[Marvel family]], the family of rank-3 temperaments where it is tempered out
* [[Marvel temperaments]], a collection of rank-2 temperaments where it is tempered out
* [[Marvel chords]]
* [[Small comma]]
* [[Small comma]]
* [[Gallery of just intervals]]
* [[Gallery of just intervals]]