2187/2176: Difference between revisions

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{{Infobox Interval
{{Infobox Interval
| JI glyph =
| Ratio = 2187/2176
| Monzo = -7 7 0 0 0 0 -1
| Cents = 8.72960
| Name = septendecimal schisma
| Name = septendecimal schisma
| Color name =  
| Color name = L17u-2, lasu negative 2nd,<br>Lasu comma
| FJS name = d-2<sub>17</sub>
| Comma = yes
| Sound =  
}}
}}


The '''septendecimal schisma''', '''2187/2176''', is a [[17-limit]] [[comma]] measuring about 8.7 cents. Although several times in size, it shares similarities with the [[schisma]] – while the schisma is the amount by which [[16/15]] deviates from [[2187/2048]], the septendecimal schisma is the amount by which [[17/16]] deviates from 2187/2048.  
The '''septendecimal schisma'''<ref>[https://marsbat.space/pdfs/HEJI2legend+series.pdf The Helmholtz-Ellis JI Pitch Notation (HEJI)]</ref>, '''2187/2176''', is a [[small comma|small]] [[17-limit]] [[comma]] measuring about 8.7{{cent}}.  


Besides the relationship above, it is also the difference between [[18/17]] and [[256/243]], between [[24/17]] and [[1024/729]], and their respective inverses. Furthermore, it and the septendecimal comma [[4131/4096]] make a [[Pythagorean comma]].  
Although several times in size, it shares similarities with the [[schisma]] – while the schisma is the amount by which [[16/15]] deviates from [[2187/2048]], the septendecimal schisma is the amount by which [[17/16]] deviates from 2187/2048, which means it is the difference between [[17/1|17th harmonic]] and a stack of seven [[3/2]] perfect fifths.  


The septendecimal schisma is significant in [[Helmholtz-Ellis notation]] (2020 version) as the 17-limit formal comma which translates a Pythagorean interval to a nearby septendecimal interval. Consequently, 17/16 is represented as an augmented unison. In [[Functional Just System]], however, that role is taken by 4131/4096, so 17/16 is represented as a minor second.  
Besides the relationship above, it is also the difference between [[18/17]] and [[256/243]], between [[24/17]] and [[1024/729]], between [[81/64]] and [[34/27]], and their respective inverses. Furthermore, it and the septendecimal comma [[4131/4096]] make a [[Pythagorean comma]].  


== See also ==
The septendecimal schisma is significant in [[Helmholtz-Ellis notation]] (2020 version) as the 17-limit formal comma which translates a Pythagorean interval to a nearby septendecimal interval. Consequently, 17/16 is represented as an augmented unison. In the [[Functional Just System]], however, that role is taken by [[4131/4096]], so 17/16 is represented as a minor second.
* [[Comma]]


[[Category:17-limit]]
== References ==
[[Category:Comma]]
<references/>
[[Category:Ratio]]
 
[[Category:Commas named for their regular temperament properties]]