225/224: Difference between revisions

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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]].
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.


== Temperaments ==
== Temperaments ==

Revision as of 22:49, 7 January 2022

Interval information
Ratio 225/224
Factorization 2-5 × 32 × 52 × 7-1
Monzo [-5 2 2 -1
Size in cents 7.711523¢
Names septimal kleisma,
marvel comma
Color name ryy-2, ruyoyo negative 2nd
FJS name [math]\displaystyle{ \text{d}{-2}^{25}_{7} }[/math]
Special properties square superparticular,
reduced
Tenney height (log2 nd) 15.6211
Weil height (log2 max(n, d)) 15.6276
Wilson height (sopfr(nd)) 33
Open this interval in xen-calc
English Wikipedia has an article on:

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 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.

Temperaments

Tempering out this comma leads to the marvel family of temperaments, which enables marvel chords.

See also