18/17: Difference between revisions

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Simplify the "terminology and notation" section since it's addressed in the 17-limit page
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== Terminology and notation ==
== Terminology and notation ==
There exists a disagreement in different conceptualization systems on whether 18/17 should be a [[diatonic semitone]] or a [[chromatic semitone]]. In the [[Functional Just System]], it is a chromatic semitone, separated by [[4131/4096]] from [[2187/2048]], the Pythagorean chromatic semitone. In [[Helmholtz-Ellis notation]], it is a diatonic semitone, separated by [[2187/2176]] from [[256/243]], the Pythagorean diatonic semitone. The term "small septendecimal semitone" omits the diatonic/chromatic part 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 18/17 specifically:
* In the [[Functional Just System]], it is a chromatic semitone, separated by [[4131/4096]] from the [[2187/2048|Pythagorean augmented unison (2187/2048)]].  
* In [[Helmholtz-Ellis notation]], it is a diatonic semitone, separated by [[2187/2176]] from the [[256/243|Pythagorean minor second (256/243)]].
 
The term ''small septendecimal semitone'' omits the diatonic/chromatic part and only describes its melodic property i.e. the size. It is said in contrast to the large septendecimal semitone of 18/17.  


== See also ==
== See also ==
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* [[Gallery of just intervals]]
* [[Gallery of just intervals]]
* [[List of superparticular intervals]]
* [[List of superparticular intervals]]
* [[18/17 equal-step tuning]] – equal multiplication of this interval
* [[1ed18/17]] – equal multiplication of this interval


[[Category:Second]]
[[Category:Second]]
[[Category:Chroma]]
[[Category:Chroma]]
[[Category:Semitone]]
[[Category:Semitone]]

Revision as of 08:17, 4 January 2024

Interval information
Ratio 18/17
Subgroup monzo 2.3.17 [1 2 -1
Size in cents 98.95459¢
Name small septendecimal semitone
Color name 17u1, su unison
FJS name [math]\displaystyle{ \text{A1}_{17} }[/math]
Special properties superparticular,
reduced
Tenney height (log2 nd) 8.25739
Weil height (log2 max(n, d)) 8.33985
Wilson height (sopfr(nd)) 25

[sound info]
Open this interval in xen-calc

In 17-limit just intonation, 18/17 is the small septendecimal semitone of about 99¢. It is very close to 12edo's "half step" of 100¢, and fairly close to the "large septendecimal semitone" of 17/16 (~105¢).

Terminology and notation

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 HC17. See 17-limit for a detailed discussion.

For 18/17 specifically:

The term small septendecimal semitone omits the diatonic/chromatic part and only describes its melodic property i.e. the size. It is said in contrast to the large septendecimal semitone of 18/17.

See also