Keemic chords: Difference between revisions

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<h2>IMPORTED REVISION FROM WIKISPACES</h2>
A '''keemic chord''' is an [[11-odd-limit]] [[essentially tempered chord]] in the [[keemic]] temperament. Since [[100/99]] is [[tempering out|tempered out]], [[ptolemismic chords]] are also keemic chords; since [[385/384]] is tempered out, [[keenanismic chords]] are also keemic chords. Aside from these, there are also essentially keemic tempered chords.  
This is an imported revision from Wikispaces. The revision metadata is included below for reference:<br>
: This revision was by author [[User:genewardsmith|genewardsmith]] and made on <tt>2011-10-25 18:02:53 UTC</tt>.<br>
: The original revision id was <tt>268530672</tt>.<br>
: The revision comment was: <tt></tt><br>
The revision contents are below, presented both in the original Wikispaces Wikitext format, and in HTML exactly as Wikispaces rendered it.<br>
<h4>Original Wikitext content:</h4>
<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">A //magical seventh// is an 11-limit essentially tempered dyadic chord consisting of three sharp minor thirds and an 8/7, in other words a 6/5-6/5-6/5-8/7 chord, which closes at the octave since both 99/98 and 385/384 (and therefore 875/864) are tempered out. This means that in the 11-limit 4&amp;7&amp;15 planar temperament tempering these out, the chord is the tempering of 1-6/5-16/11-7/4. In an optimized tuning for the 4&amp;7&amp;15 temperament, the marvel comma 225/224 shrinks in size and may reverse direction, and adding it to the list of commas does little tuning damage; this results in 11-limit magic temperament, which has the same optimal patent val ([[104edo]].) Hence while it by definition it merely requires the 4&amp;7&amp;15 temperament, it can for the most part be regarded as a chord of [[magic]] (19&amp;22) temperament.


However, this chord also exists and has low complexity in 11-limit [[Superpyth#Suprapyth|suprapyth]] temperament. One is found in the 7-note MOS.</pre></div>
The most basic of these is the '''magical seventh chord''', consisting of three sharp [[6/5|classical minor thirds]] and a [[8/7|septimal whole tone]], which closes at the [[octave]] since both [[100/99]] and [[385/384]] (and therefore [[875/864]]) are [[tempering out|tempered out]]. This means the chord is the tempering of  
<h4>Original HTML content:</h4>
* 1–6/5–16/11–7/4 with steps 6/5, 6/5, 6/5, 8/7.  
<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;magical seventh chord&lt;/title&gt;&lt;/head&gt;&lt;body&gt;A &lt;em&gt;magical seventh&lt;/em&gt; is an 11-limit essentially tempered dyadic chord consisting of three sharp minor thirds and an 8/7, in other words a 6/5-6/5-6/5-8/7 chord, which closes at the octave since both 99/98 and 385/384 (and therefore 875/864) are tempered out. This means that in the 11-limit 4&amp;amp;7&amp;amp;15 planar temperament tempering these out, the chord is the tempering of 1-6/5-16/11-7/4. In an optimized tuning for the 4&amp;amp;7&amp;amp;15 temperament, the marvel comma 225/224 shrinks in size and may reverse direction, and adding it to the list of commas does little tuning damage; this results in 11-limit magic temperament, which has the same optimal patent val (&lt;a class="wiki_link" href="/104edo"&gt;104edo&lt;/a&gt;.) Hence while it by definition it merely requires the 4&amp;amp;7&amp;amp;15 temperament, it can for the most part be regarded as a chord of &lt;a class="wiki_link" href="/magic"&gt;magic&lt;/a&gt; (19&amp;amp;22) temperament.&lt;br /&gt;
 
&lt;br /&gt;
In an optimized tuning for the keemic temperament, the [[marvel]] comma [[225/224]] shrinks in size and may reverse direction, and adding it to the list of commas does little tuning [[damage]]; this results in 11-limit [[magic]] temperament, which has the same [[optimal patent val]] ([[104edo]]). Hence [[magic]] (19&amp;22) temperament is practically the most accurate temperament that include this chord. Magic, however, does give it a [[Graham complexity]] of 12, so it does not appear that often.
However, this chord also exists and has low complexity in 11-limit &lt;a class="wiki_link" href="/Superpyth#Suprapyth"&gt;suprapyth&lt;/a&gt; temperament. One is found in the 7-note MOS.&lt;/body&gt;&lt;/html&gt;</pre></div>
 
Other temperaments that feature this chord prominently include 11-limit [[keemun]], [[superkleismic]], [[porcupine]] and [[doublewide]].
 
For other tetrads, there are
* 1–5/4–16/11–9/5 with steps 5/4, 7/6, 5/4, 10/9;  
* 1–12/11–5/4–9/5 with steps 12/11, 8/7, 16/11, 10/9, and its inverse
* 1–12/11–6/5–7/4 with steps 12/11, 10/9, 16/11, 8/7.  
 
For pentads, there are
* 1–12/11–5/4–3/2–9/5 with steps 12/11, 8/7, 6/5, 6/5, 10/9, and its inverse
* 1–6/5–11/8–3/2–5/3 with steps 6/5, 8/7, 12/11, 10/9, 6/5;  
* 1–5/4–11/8–3/2–12/7 with steps 5/4, 11/10, 12/11, 8/7, 7/6, and its inverse
* 1–12/11–6/5–3/2–7/4 with steps 12/11, 11/10, 5/4, 7/6, 8/7.
 
The count of keemic chords is therefore tetrads: 4, and pentads: 4, for a total of 8.
 
[[Category:11-odd-limit chords]]
[[Category:Essentially tempered chords]]
[[Category:Tetrads]]
[[Category:Pentads]]
[[Category:Keemic]]