65/64: Difference between revisions
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In [[just intonation]], '''65/64''', the '''wilsorma''', is a [[superparticular]] interval of around 26.8¢, nearly a quarter of a semitone or eighth of a tone. It belongs to the [[13-prime-limit]], which means that the highest prime in the ratio is 13. 65 is 5 times 13, which means that 65/64 can be treated as a harmonic 13th above a harmonic 5th or vice versa. It is the difference between [[5/4]] and [[16/13]]; [[8/5]] and [[13/8]]; [[13/12]] and [[16/15]]; [[15/8]] and [[24/13]], [[13/10]] and [[32/25]]; [[20/13]] and [[25/16]], and of course, infinitely many other pairs of just intervals. It differs from the septimal comma [[64/63]] by [[4096/4095]] and from the syntonic comma [[81/80]] by [[325/324]]. | In [[just intonation]], '''65/64''', the '''wilsorma''', is a [[superparticular]] interval of around 26.8¢, nearly a quarter of a semitone or eighth of a tone. It belongs to the [[13-prime-limit]], which means that the highest prime in the ratio is 13. 65 is 5 times 13, which means that 65/64 can be treated as a harmonic 13th above a harmonic 5th or vice versa. It is the difference between [[5/4]] and [[16/13]]; [[8/5]] and [[13/8]]; [[13/12]] and [[16/15]]; [[15/8]] and [[24/13]], [[13/10]] and [[32/25]]; [[20/13]] and [[25/16]], and of course, infinitely many other pairs of just intervals. It differs from the septimal comma [[64/63]] by [[4096/4095]] and from the syntonic comma [[81/80]] by [[325/324]]. | ||
Tempering it out turns 5/4 and 13/8 into [[Octave_complement|octave complements]] of one-another. This is particularly useful in many [[13-limit]] [[Magic_family|magic family]] extensions, as it means they are very simply mapped to plus and minus one generator. | |||
== See also == | == See also == | ||
Revision as of 17:29, 12 June 2021
| Interval information |
reduced,
reduced harmonic
In just intonation, 65/64, the wilsorma, is a superparticular interval of around 26.8¢, nearly a quarter of a semitone or eighth of a tone. It belongs to the 13-prime-limit, which means that the highest prime in the ratio is 13. 65 is 5 times 13, which means that 65/64 can be treated as a harmonic 13th above a harmonic 5th or vice versa. It is the difference between 5/4 and 16/13; 8/5 and 13/8; 13/12 and 16/15; 15/8 and 24/13, 13/10 and 32/25; 20/13 and 25/16, and of course, infinitely many other pairs of just intervals. It differs from the septimal comma 64/63 by 4096/4095 and from the syntonic comma 81/80 by 325/324.
Tempering it out turns 5/4 and 13/8 into octave complements of one-another. This is particularly useful in many 13-limit magic family extensions, as it means they are very simply mapped to plus and minus one generator.