17/12: Difference between revisions

+terminology and notation
Simplify the "terminology and notation" section since it's addressed in the 17-limit page
 
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In [[17-limit]] [[just intonation]], '''17/12''' is the '''larger septendecimal tritone''', measuring very nearly 603¢. Its inversion is the smaller septendecimal tritone, [[24/17]], and the interval that separates them is the small [[comma]] [[289/288]], about 6¢. This difference is usually negligible, and tempering out this comma allows the 600¢ half-octave to function as both septendecimal tritones. Thus, every even-numbered [[edo]] system contains a close approximation to these intervals.
In [[17-limit]] [[just intonation]], '''17/12''' is the '''large septendecimal tritone''', measuring very nearly 603¢. Its inversion is the smaller septendecimal tritone, [[24/17]], and the interval that separates them is the small [[comma]] [[289/288]], about 6¢. This difference is usually negligible, and tempering out this comma allows the 600¢ half-octave to function as both septendecimal tritones. Thus, every even-numbered [[edo]] system contains a close approximation to these intervals.


17/12 is the [[mediant]] between the two septimal tritones [[7/5]] and [[10/7]].
17/12 is the [[mediant]] between the two septimal tritones [[7/5]] and [[10/7]].


== Terminology and notation ==
== Terminology and notation ==
There exists a disagreement in different conceptualization systems on whether 17/12 should be an augmented fourth or a diminished fifth. In [[Functional Just System]], it is a diminished fifth, separated by [[4131/4096]] from [[1024/729]], the Pythagorean diminished fifth In [[Helmholtz-Ellis notation]], it is an augmented fourth, separated by [[2187/2176]] from [[729/512]], the Pythagorean augmented fourth. The term "large septendecimal tritone" omits the distinction and only describes its melodic property i.e. the size.  
Conceptualization systems disagree on whether [[17/16]] should be a [[diatonic semitone]] or a [[chromatic semitone]], and as a result the disagreement propagates to all intervals of [[harmonic class|HC17]]. See [[17-limit]] for a detailed discussion.  


In practice, the interval category may, arguably, vary by context. One solution for the JI user who uses expanded [[circle-of-fifths notation]] is to prepare a [[Pythagorean comma]] accidental so that the interval can be notated in either category.
For 17/12 specifically:
* In [[Functional Just System]], it is a diminished fifth, separated by [[4131/4096]] from the [[1024/729|Pythagorean diminished fifth (1024/729)]].  
* In [[Helmholtz-Ellis notation]], it is an augmented fourth, separated by [[2187/2176]] from the [[729/512|Pythagorean augmented fourth (729/512)]].
 
The term ''large septendecimal tritone'' omits the distinction and only describes its melodic property i.e. the size. It is said in contrast to the small septendecimal tritone of 24/17.  


== See also ==
== See also ==