15/14: Difference between revisions

Wikispaces>FREEZE
No edit summary
Rewrite to better address the names (displacing "septimal major semitone", not attested anywhere)
 
(32 intermediate revisions by 14 users not shown)
Line 1: Line 1:
'''15/14'''
{{Infobox Interval
|-1 1 1 -1>
| Name = septimal diatonic semitone, aberschismic chromatic semitone, major chromatic semitone
| Color name = ry1, ruyo unison
| Sound = jid_15_14_pluck_adu_dr220.mp3
}}
{{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>.


119.44281 cents
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]]
* [[7/6]] and [[5/4]]
* [[6/5]] and [[9/7]]
* [[14/9]] and [[5/3]]
* [[8/5]] and [[12/7]]
* [[7/4]] and [[15/8]]
* [[9/5]] and [[27/14]]


[[File:jid_15_14_pluck_adu_dr220.mp3]] [[:File:jid_15_14_pluck_adu_dr220.mp3|sound sample]]
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]]
* [[7/5]] and [[3/2]]


The septimal diatonic semitone, 15/14, is a [[superparticular|superparticular]] ratio with a numerator which is the fifth [http://en.wikipedia.org/wiki/Triangular_number triangular number].
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]]
* [[26/15]] and [[13/7]]


It may be found as the interval between many [[7-limit|7-limit]] ratios, including:
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]]).


<ul><li>16/15 and 8/7</li><li>14/13 and 15/13</li><li>7/6 and 5/4</li><li>6/5 and 9/7</li><li>14/11 and 15/11</li><li>4/3 and 10/7</li><li>7/5 and 3/2</li><li>22/15 and 11/7</li><li>14/9 and 5/3</li><li>8/5 and 12/7</li><li>26/15 and 13/7</li><li>7/4 and 15/8</li></ul>
== 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.


[http://en.wikipedia.org/wiki/Septimal_diatonic_semitone http://en.wikipedia.org/wiki/Septimal_diatonic_semitone]
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 ==
* [[28/15]] – its [[octave complement]]
* [[7/5]] – its [[fifth complement]]
* [[List of superparticular intervals]]
* [[Gallery of just intervals]]
 
== References ==
<references/>
 
[[Category:Semitone]]
[[Category:Chroma]]
[[Category:Mercurial]]