256/243: Difference between revisions

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{{interwiki
| de = 256/243
| en = 256/243
| es =
| ja =
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{{Infobox Interval
{{Infobox Interval
| Ratio = 256/243
| Name = Pythagorean limma, Pythagorean diatonic semitone, blackwood comma
| Monzo = 8 -5
| Color name = sw2, sawa 2nd
| Cents = 90.225
| Name = Pythagorean limma, <br>Pythagorean diatonic semitone
| Sound = jid_256_243_pluck_adu_dr220.mp3
| Sound = jid_256_243_pluck_adu_dr220.mp3
| FJS name = m2
| Comma = yes
}}
}}
{{Wikipedia| Semitone #Pythagorean tuning }}
'''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 ==
This interval is well approximated by any tuning generated with accurate octaves and fifths. For example, [[53edo|4\53]] is a very good approximation.
== 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.


The '''Pythagorean limma''', or '''Pythagorean diatonic semitone''', is the interval of size 256/243 = 2<sup>8</sup>/3<sup>5</sup> (about 90.2¢), which is the diatonic semitone in [[Pythagorean tuning]]. It can be generated by stacking five [[4/3]] just perfect fourths and octave-reducing the resulting interval.
== Notation ==
In musical notations that employ the [[5L 2s|diatonic]] [[chain-of-fifths notation|chain-of-fifths]], such as the [[ups and downs notation]], the limma is represented by the distances between B and C, as well as between E and F.


== Temperament ==
The scale is structured with the following step pattern:
When this ratio is taken as a comma to be tempered, it produces [[blackwood]] temperament. Edos tempering it out include [[5edo]], [[10edo]], [[15edo]], [[20edo]], [[25edo]] and [[30edo]].
* A to B: [[9/8|whole tone]]
* B to C: [[256/243|limma]]
* C to D: [[9/8|whole tone]]
* D to E: [[9/8|whole tone]]
* E to F: [[256/243|limma]]
* F to G: [[9/8|whole tone]]
* G to A: [[9/8|whole tone]]
This pattern highlights the placement of the limma intervals between the note pairs above, distinguishing them from the [[9/8|whole tone]] that occur between the other note pairs.


== See also ==
== See also ==
* [[243/128]] – its [[octave complement]]
* [[243/128]] – its [[octave complement]]
* [[729/512]] – its [[fifth complement]]
* [[729/512]] – its [[fifth complement]]
* [[16/15]] – the classic (5-limit) diatonic semitone
* [[Gallery of just intervals]]
* [[Gallery of just intervals]]
* [[Medium comma]]
* [[Medium comma]]
* [[Pythagorean tuning]]
* [[Pythagorean tuning]]
* [[53edo|4\53]] is a very good approximation of the interval


[[Category: 3-limit]]
[[Category:Second]]
[[Category: Interval]]
[[Category:Semitone]]
[[Category: Interval ratio]]
[[Category:Blackwood]]
[[Category: Pythagorean]]
[[Category:Commas named after composers]]
[[Category: Second]]
[[Category: Semitone]]