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'''Decaononic''' technique is the way of playing and composing where a '''[[tone]]''' is considered to be equal to '''[[10/9]]'''.
The '''decaononic'''{{idiosyncratic}} technique is the way of playing and composing where a [[tone]] is considered to be equal to [[10/9]]. It is a set of temperaments that may interpret this function differently.
 
It is a set of temperaments that may interpret this function differently.  


== Origin ==
== Origin ==
In 5-limit just intotation and most of the music theory that comes with it, 10/9 is viewed as a secondary tone as opposed to [[9/8]]. In general, when the [[81/80|difference]] between the two is eliminated, what it really means is that the "tone" is set to equal to 9/8 and the tuning completely misses 10/9. This is primarily because 9/8 and an octave are equal to a stack of two perfect fifths. 10/9 therefore in this paradigm only occurs as a side product of 9/8, and it isn't an interval of its own.  
In 5-limit just intonation and most of the music theory that comes with it, 10/9 is viewed as a secondary tone as opposed to [[9/8]]. In general, when the [[81/80|difference]] between the two is eliminated, what it really means is that the "tone" is set to equal to 9/8 and the tuning completely misses 10/9. This is primarily because 9/8 and an octave are equal to a stack of two perfect fifths. 10/9 therefore in this paradigm only occurs as a side product of 9/8, and it isn't an interval of its own.  


While there are temperaments which use 10/9 as a generator for various purposes (such as [[Porcupine]]), decaononic means that 10/9 is ''the tone,'' and 9/8 is not as emphasized.
While there are temperaments which use 10/9 as a generator for various purposes (such as [[Porcupine]]), decaononic means that 10/9 is ''the tone,'' and 9/8 is not as emphasized.


== Theory ==
== Theory ==
The name "decaononic" comes from Greek and Latin words for 10 and 9 respectively, and a letter o meaning "over", as in "[[otonal]]". In this system, one tone is set to be 10/9, about 182.4 cents, and other intervals may have multiple interpretations.  
The name "decaononic", proposed by [[Eliora]], comes from Greek and Latin words for 10 and 9 respectively, and a letter o meaning "over", as in "[[otonal]]". In this system, one tone is set to be 10/9, about 182.4 cents, and other intervals may have multiple interpretations.  


=== Whole tone scale ===
=== Whole tone scale ===
{{Main|10/9ths equal temperament}}
{{Main|10/9ths equal temperament}}
Decaononic temperaments can be represented in EDOs which compress the 12edo scale to get the major second to be equal to 10/9. In [[79edo]], for example, a whole tone itself contains a mini-12edo keymap inside it, and the final 7 notes are a truncated tetrachord. If played naively, this produces a rather flat fifth of 638.413c just, or 637.974c (79edo). In an effect this makes for a [[Glacial7]]-type scale.
Decaononic temperaments can be represented in EDOs which compress the 12edo scale to get the major second to be equal to 10/9. In [[79edo]], for example, a whole tone itself contains a mini-12edo keymap inside it, and the final 7 notes are a truncated tetrachord. If played naively, this produces an extremely flat fifth of 638.413c just, or 637.974c (79edo). In an effect this makes for a [[Glacial7]]-type scale.


=== Meantone ===
=== Meantone ===
Meantone decaononic temperament assigns the perfect fifth to split the major ninth, as normal meantone would, in two. This therefore results in the fifth size of <math>\sqrt{20/9} = 1.490712...</math>, or about 691.2019 cents. The amount by which the fifth is flattened is equal to <math>\sqrt{81/80} = 1.0062...</math>, therefore this is effectively the same as '''1/2-comma meantone'''.  
Meantone decaononic temperament assigns the perfect fifth to split the major ninth, as normal meantone would, in two. This therefore results in the fifth size of <math>\sqrt{20/9} = 1.490712...</math>, or about 691.2019 cents. The amount by which the fifth is flattened is equal to <math>\sqrt{81/80} = 1.0062...</math>, therefore this is effectively the same as [[1/2 syntonic comma meantone|1/2-comma meantone]].  


=== Devil's dozen ===
=== Devil's dozen ===
Devil's dozen technique is playing in [[13edo]] as if it were 12edo. Since 10/9 is closely equal to 2\13 of the octave, it can be assigned to be a 13edo whole tone. The resulting comma that is tempered out is {{monzo|-11 26 -13}} or fully 2541865828329/2500000000000 - devil's tridecalimma.
Devil's dozen technique is playing in [[13edo]] as if it were 12edo. Since 10/9 is closely equal to 2\13 of the octave, it can be assigned to be a 13edo whole tone. The resulting comma that is tempered out is {{monzo|-11 26 -13}} or fully 2541865828329/2500000000000 - devil's tridecalimma.
=== Hitchcock archaeotonic ===
10/9 is found at -3 [[hitchcock]] generators, and the use of this index-3 subset in a decaononic manner produces an [[6L 1s|archaeotonic (6L 1s)]] scale combining six 10/9 tones and a [[16/15]] semitone. This is neither especially accurate nor especially inaccurate, and fits well with 13edo.
{| class="wikitable"
|+
!Tones
!Interval
|-
|0
|[[1/1]]
|-
|1
|[[10/9]]
|-
|2
|[[16/13]], [[21/17]]
|-
|3
|[[11/8]], [[15/11]]
|-
|4
|[[32/21]]
|-
|5
|[[27/16]]
|-
|6
|[[15/8]]
|}


== See also ==
== See also ==
* [[Minortone]]
* [[Minortone]]


[[Category:10/9]]
[[Category:Whole tone]]
[[Category:Whole tone]]