256/243: Difference between revisions

Temperaments: -ahistorical stuff
Expand after 2187/2048
 
(6 intermediate revisions by 5 users not shown)
Line 1: Line 1:
{{interwiki
| de = 256/243
| en = 256/243
| es =
| ja =
}}
{{Infobox Interval
{{Infobox Interval
| Name = Pythagorean limma, Pythagorean diatonic semitone, blackwood comma
| Name = Pythagorean limma, Pythagorean diatonic semitone, blackwood comma
Line 7: Line 13:
{{Wikipedia| Semitone #Pythagorean tuning }}
{{Wikipedia| Semitone #Pythagorean tuning }}


The interval '''256/243''', the '''Pythagorean limma''', or '''Pythagorean diatonic semitone''' factors as 2<sup>8</sup>/3<sup>5</sup>, is about 90.2 [[cent]]s in size, and is the [[diatonic semitone]] in [[Pythagorean tuning]]. It can be generated by stacking five [[4/3]] just perfect fourths and [[Octave reduction|octave-reducing]] the resulting interval.
'''256/243''', the '''Pythagorean limma''' or '''Pythagorean diatonic semitone''', is the [[diatonic semitone]] in [[Pythagorean tuning]]. In other words, it is the [[3-limit]] minor second. It factors as 2<sup>8</sup>/3<sup>5</sup>, and is about 90.2 [[cent]]s in size. It can be generated by stacking five [[4/3]] just perfect fourths and [[octave reduction|octave-reducing]] the resulting interval, or equivalently by decreasing 4/3 by two [[9/8]] major seconds. Unlike the situation in [[meantone]] tunings, it is smaller, not larger, than the corresponding [[chromatic semitone]], which is the Pythagorean augmented unison of [[2187/2048]].  


== Approximation ==
== Approximation ==
Line 13: Line 19:


== Temperaments ==
== Temperaments ==
When this ratio is taken as a comma to be tempered in the [[5-limit]], it produces the [[blackwood]] temperament, and it may be called the '''blackwood comma''', named after [[Easley Blackwood Jr]]. Edos tempering it out include [[5edo]], [[10edo]], [[15edo]], [[20edo]], [[25edo]] and [[30edo]]. See [[limmic temperaments]] for a number of other temperaments where it is tempered out.
When this ratio is taken as a comma to be tempered in the [[5-limit]], it produces the [[blackwood]] temperament, and it may be called the '''blackwood comma''', named after [[Easley Blackwood Jr]]. Edos tempering it out include [[5edo]], [[10edo]], [[15edo]], [[20edo]], [[25edo]] and [[30edo]]. See [[Limmic temperaments]] for a number of other temperaments where it is tempered out.


== Notation ==
== Notation ==
Line 39: Line 45:
[[Category:Semitone]]
[[Category:Semitone]]
[[Category:Blackwood]]
[[Category:Blackwood]]
[[Category:Commas named after polymaths]]
[[Category:Commas named after controversial individuals]]
[[Category:Commas named after composers]]
[[Category:Commas named after composers]]