40/21: Difference between revisions

@@ Line 1: / Line 1: @@
-'''40/21'''
+{{Infobox Interval
-|3 -1 1 -1&gt;
+| Name = septimal acute major seventh, aberschismic major seventh
+| Color name = ry7, ruyo 7th
+| Sound = jid_40_21_pluck_adu_dr220.mp3
+}}
+'''40/21''', conventionally known as the '''septimal acute major seventh''', is an interval in [[7-limit]] [[just intonation]] measuring about 1115.5 [[cent]]s. Despite being approximated by the diminished octave in systems like septimal [[meantone]], and even being called the ''septimal diminished octave'' by some musicians due to analogy with [[21/20]] being called the "septimal chromatic semitone", 40/21 functions as a major seventh, as is supported by [[Sagittal notation]], [[Helmholtz–Ellis notation]] and [[Functional Just System]], viewed as the [[243/128|Pythagorean major seventh (243/128)]] altered by an [[aberschisma]]. This gives rise to the more precise name '''aberschismic major seventh'''.
-.5328 cents
+== Approximation ==
+{{Interval edo approximation|40/21}}
-[[File:jid_40_21_pluck_adu_dr220.mp3]] [[:File:jid_40_21_pluck_adu_dr220.mp3|sound sample]]      [[Category:todo:expand]]
+== See also ==
+* [[21/20]] – its [[octave complement]]
+* [[Gallery of just intervals]]
+[[Category:Seventh]]
+[[Category:Major seventh]]