256/243: Difference between revisions

Wikispaces>genewardsmith
**Imported revision 244949379 - Original comment: **
 
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<h2>IMPORTED REVISION FROM WIKISPACES</h2>
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This is an imported revision from Wikispaces. The revision metadata is included below for reference:<br>
| de = 256/243
: This revision was by author [[User:genewardsmith|genewardsmith]] and made on <tt>2011-08-08 21:56:24 UTC</tt>.<br>
| en = 256/243
: The original revision id was <tt>244949379</tt>.<br>
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: The revision comment was: <tt></tt><br>
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The revision contents are below, presented both in the original Wikispaces Wikitext format, and in HTML exactly as Wikispaces rendered it.<br>
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<h4>Original Wikitext content:</h4>
{{Infobox Interval
<div style="width:100%; max-height:400pt; overflow:auto; background-color:#f8f9fa; border: 1px solid #eaecf0; padding:0em"><pre style="margin:0px;border:none;background:none;word-wrap:break-word;white-space: pre-wrap ! important" class="old-revision-html">The Pythagorean limma, or Pythagorean semitone, is the interval of size 256/243 = 2^8/3^5, which is the diatonic semitone in Pythagorean tuning. </pre></div>
| Name = Pythagorean limma, Pythagorean diatonic semitone, blackwood comma
<h4>Original HTML content:</h4>
| Color name = sw2, sawa 2nd
<div style="width:100%; max-height:400pt; overflow:auto; background-color:#f8f9fa; border: 1px solid #eaecf0; padding:0em"><pre style="margin:0px;border:none;background:none;word-wrap:break-word;width:200%;white-space: pre-wrap ! important" class="old-revision-html">&lt;html&gt;&lt;head&gt;&lt;title&gt;256_243&lt;/title&gt;&lt;/head&gt;&lt;body&gt;The Pythagorean limma, or Pythagorean semitone, is the interval of size 256/243 = 2^8/3^5, which is the diatonic semitone in Pythagorean tuning.&lt;/body&gt;&lt;/html&gt;</pre></div>
| Sound = jid_256_243_pluck_adu_dr220.mp3
| 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.
 
== 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.
 
The scale is structured with the following step pattern:
* 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 ==
* [[243/128]] – its [[octave complement]]
* [[729/512]] – its [[fifth complement]]
* [[16/15]] – the classic (5-limit) diatonic semitone
* [[Gallery of just intervals]]
* [[Medium comma]]
* [[Pythagorean tuning]]
 
[[Category:Second]]
[[Category:Semitone]]
[[Category:Blackwood]]
[[Category:Commas named after composers]]