33/32: Difference between revisions

| Name = undecimal comma<br>undecimal quarter tone<br>al-Farabi (Alpharabius) quarter tone

'''33/32''', the '''undecimal comma''', '''undecimal quarter tone''', or '''al-Farabi (Alpharabius) quarter tone''', is a [[superparticular]] [[ratio]] which differs by a [[385/384|keenanisma (385/384)]], from the [[36/35|septimal quarter tone (36/35)]]. Raising a just [[4/3|perfect fourth (4/3)]] by the al-Farabi quarter-tone leads to the [[11/8|undecimal super-fourth (11/8)]]. Raising it instead by 36/35 leads to the [[48/35|septimal super-fourth (48/35)]] which approximates 11/8.

Arguably 33/32 could have been used as a melodic interval in the Greek Enharmonic Genus. The resulting tetrachord would include 32:33:34 within the interval of a perfect fourth. This ancient Greek scale can be approximated in [[22edo]] and [[24edo]], if the comma 1089/1088 is tempered so that 33/32 and 34/33 are equated.

 

33/32 is significant in [[Functional Just System]] as the undecimal formal comma which translates a Pythagorean interval to a nearby undecimal interval. Apart from the aforementioned relationship between 4/3 and 11/8, it is also the interval between [[32/27]] and [[11/9]], and between [[9/8]] and [[12/11]].