15/14: Difference between revisions
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* [[26/15]] and [[13/7]] | * [[26/15]] and [[13/7]] | ||
== | == Theory == | ||
15/14 is traditionally called a ''diatonic semitone'', perhaps for its proximity (and conflation in systems such as septimal [[meantone]] and [[marvel]]) with the classic diatonic semitone [[16/15]]. However, 15/14 is a ''[[Wikipedia:chromatic semitone|chromatic semitone]]'' in both [[Helmholtz–Ellis notation]] and the [[Functional Just System]], viewed as the apotome [[2187/2048]] altered by [[5120/5103]]. [[Marc Sabat]] has taken to call it the ''major chromatic semitone'' in the same material where [[21/20]] is also named as the minor diatonic semitone<ref>Marc Sabat. [https://masa.plainsound.org/pdfs/crystal-growth.pdf ''Three Crystal Growth Algorithms in 23-limit constrained Harmonic Space'']. Plainsound Music Edition, 2008.</ref>. | 15/14 is traditionally called a ''diatonic semitone'', perhaps for its proximity (and conflation in systems such as septimal [[meantone]] and [[marvel]]) with the classic diatonic semitone [[16/15]]. However, 15/14 is a ''[[Wikipedia:chromatic semitone|chromatic semitone]]'' in both [[Helmholtz–Ellis notation]] and the [[Functional Just System]], viewed as the apotome [[2187/2048]] altered by [[5120/5103]]. [[Marc Sabat]] has taken to call it the ''major chromatic semitone'' in the same material where [[21/20]] is also named as the minor diatonic semitone<ref>Marc Sabat. [https://masa.plainsound.org/pdfs/crystal-growth.pdf ''Three Crystal Growth Algorithms in 23-limit constrained Harmonic Space'']. Plainsound Music Edition, 2008.</ref>. | ||
15/14 is the difference between certain [[interval qualities]] of thirds and sixths: between (classic) minor and supermajor, and between subminor and (classic) major. These are the pairs of intervals separated by 15/14: | |||
* 7/6 and 5/4 (otonal thirds) | |||
* 6/5 and 9/7 (utonal thirds) | |||
* 14/9 and 5/3 (otonal sixths) | |||
* 8/5 and 12/7 (utonal sixths) | |||
[[36/35]] separates the otonal pairs from the utonal pairs; 4/3 separates the thirds from the sixths. | |||
They can also be organized into pairs of intervals differing by 36/35: | |||
* 7/6 and 6/5 (minor thirds) | |||
* 5/4 and 9/7 (major thirds) | |||
* 14/9 and 8/5 (minor sixths) | |||
* 5/3 and 12/7 (major sixths) | |||
15/14 separates the minor pairs from the major pairs; 4/3 separates the thirds from the sixths. | |||
36/35 separates 15/14 from [[25/24]] on one side and [[54/49]] on the other. | |||
== Approximation == | == Approximation == | ||