21/20: Difference between revisions

m +category
+terminology section useful for any interval name under debate
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| Monzo = -2 1 -1 1
| Monzo = -2 1 -1 1
| Cents = 84.4672
| Cents = 84.4672
| Name = minor semitone, <br>large septimal chroma
| Name = septimal minor semitone, <br>large septimal chroma
| Color name = zg2, zogu 2nd
| Color name = zg2, zogu 2nd
| FJS name = m2<sup>7</sup><sub>5</sub>
| FJS name = m2<sup>7</sup><sub>5</sub>
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'''21/20''' is a small semitone of about 85 cents. It may be found in [[7-limit]] [[just intonation]] as, for example, the difference between [[8/7]] and [[6/5]], or between [[5/3]] and [[7/4]].  
'''21/20''' is a small semitone of about 85 cents. It may be found in [[7-limit]] [[just intonation]] as, for example, the difference between [[8/7]] and [[6/5]], or between [[5/3]] and [[7/4]].  


Although called a ''chroma'' for its proximity (and conflation in systems like septimal [[meantone]]) with the major chroma [[135/128]], 21/20 is a ''diatonic semitone'' in both [[Helmholtz-Ellis notation]] and [[Functional Just System]] because it is [[5120/5103]] smaller than the Pythagorean minor second [[256/243]].  
== Terminology ==
21/20 is traditionally called a ''chroma'', perhaps for its proximity (and conflation in systems like septimal [[meantone]]) with the major chroma [[135/128]]. However, it is a ''diatonic semitone'' in both [[Helmholtz-Ellis notation]] and [[Functional Just System]], viewed as the Pythagorean minor second [[256/243]] altered by [[5120/5103]]. [[Marc Sabat]] has taken to call it the ''minor diatonic semitone'' in the same material where [[15/14]] is also named as the major chromatic semitone<ref>[https://marsbat.space/pdfs/crystal-growth.pdf Marc Sabat (2008) Three Crystal Growth Algorithms in 23-limit constrained Harmonic Space]</ref>.  
 
<references/>


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