15/14: Difference between revisions

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simplified list, added links, added categories, expanded see also section
Rewrite to better address the names (displacing "septimal major semitone", not attested anywhere)
 
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{{Infobox Interval
{{Infobox Interval
| JI glyph =
| Name = septimal diatonic semitone, aberschismic chromatic semitone, major chromatic semitone
| Ratio = 15/14
| Color name = ry1, ruyo unison
| Monzo = -1 1 1 -1
| Cents = 119.44281
| Name = septimal diatonic semitone
| Sound = jid_15_14_pluck_adu_dr220.mp3
| Sound = jid_15_14_pluck_adu_dr220.mp3
| Color name = ry1, ruyo semitone
}}
}}
'''15/14''' is a [[superparticular]] ratio with a numerator which is the fifth [http://en.wikipedia.org/wiki/Triangular_number triangular number].
{{Wikipedia|Septimal diatonic semitone}}
 
'''15/14''' is an interval in [[7-limit]] [[just intonation]] measuring about 119.4 [[cent]]s, traditionally known as the '''septimal diatonic semitone''' for its proximity (and conflation in [[marvel]] tunings such as septimal [[meantone]]) with the classical diatonic semitone [[16/15]]. However, it functions as a ''[[chromatic semitone]]'', as is supported by [[Sagittal notation]], [[Helmholtz–Ellis notation]] and the [[Functional Just System]], viewed as the [[Pythagorean apotome]] altered by an [[aberschisma]]. This gives rise to the more precise name '''aberschismic chromatic semitone''', or as [[Marc Sabat]] has taken to call it, the '''major chromatic 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>.
It may be found as the interval between many [[7-limit]] ratios, including:


Because it contains exactly one of each prime up to 7, it appears as the interval between many simple [[7-limit]] ratios. In particular, it is the difference between certain [[interval qualities]] of seconds, thirds, sixths, and sevenths: between classical minor and supermajor, and between subminor and classical major. These are the pairs of intervals separated by 15/14:
* [[28/27]] and [[10/9]]
* [[16/15]] and [[8/7]]
* [[16/15]] and [[8/7]]
* [[14/13]] and [[15/13]]
* [[7/6]] and [[5/4]]
* [[7/6]] and [[5/4]]
* [[6/5]] and [[9/7]]
* [[6/5]] and [[9/7]]
* [[14/11]] and [[15/11]]
* [[14/9]] and [[5/3]]
* [[8/5]] and [[12/7]]
* [[7/4]] and [[15/8]]
* [[9/5]] and [[27/14]]
 
In addition, it separates the perfect fourth from the larger septimal tritone, and the perfect fifth from the smaller septimal tritone:
* [[4/3]] and [[10/7]]
* [[4/3]] and [[10/7]]
* [[7/5]] and [[3/2]]
* [[7/5]] and [[3/2]]
It also arises in higher limits as the difference between:
* [[14/13]] and [[15/13]]
* [[14/11]] and [[15/11]]
* [[22/15]] and [[11/7]]
* [[22/15]] and [[11/7]]
* [[14/9]] and [[5/3]]
* [[8/5]] and [[12/7]]
* [[26/15]] and [[13/7]]
* [[26/15]] and [[13/7]]
* [[7/4]] and [[15/8]]
 
Finally, since it is a [[superparticular ratio]] with a numerator which is the fifth [[triangular number]], it is a [[triangle-particular]] ratio with factorization ([[25/24]])⋅([[36/35]]).
 
== Approximation ==
15/14 is very accurately approximated by [[10edo]] (1\10) and all [[linus]] temperaments. The [[linus comma]], 5.6{{c}}, is the amount by which a stack of ten 15/14's falls short of the octave.
 
In combination with [[19/17]] it forms a good approximation of [[golden meantone]]. The untempered combination of five 19/17's and two 15/14's leads to an interval that is sharp to an octave by the [[mercurial comma]]: (19/17)<sup>5</sup> × (15/14)<sup>2</sup> = 2 / (mercurial comma).
 
{{Interval edo approximation|max edo=131|15/14}}
 
== Temperaments ==
The following [[linear temperament]]s are [[generate]]d by a [[~]]15/14:
* [[Septidiasemi]]
* [[Subsedia]]
 
In addition, this [[fractional-octave temperament]] is generated by a ~15/14:
* [[Tertiosec]] (1\3)
 
Several [[10th-octave temperaments]] treat ~15/14 as the period, including [[decoid]] and [[linus]].
{{todo|complete list}}


== See also ==
== See also ==
* [[Gallery of Just Intervals]]
* [[28/15]] – its [[octave complement]]
* [[28/15]] its inverse interval
* [[7/5]] its [[fifth complement]]
* [http://en.wikipedia.org/wiki/Septimal_diatonic_semitone Septimal diatonic semitone - Wikipedia]
* [[List of superparticular intervals]]
* [[Gallery of just intervals]]
 
== References ==
<references/>


[[Category:7-limit]]
[[Category:Interval]]
[[Category:Semitone]]
[[Category:Semitone]]
[[Category:Superparticular]]
[[Category:Chroma]]
[[Category:todo:expand]]
[[Category:Mercurial]]