28edo: Difference between revisions

Wikispaces>hstraub
**Imported revision 238134791 - Original comment: **
Wikispaces>xenwolf
**Imported revision 239550315 - Original comment: **
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<h2>IMPORTED REVISION FROM WIKISPACES</h2>
<h2>IMPORTED REVISION FROM WIKISPACES</h2>
This is an imported revision from Wikispaces. The revision metadata is included below for reference:<br>
This is an imported revision from Wikispaces. The revision metadata is included below for reference:<br>
: This revision was by author [[User:hstraub|hstraub]] and made on <tt>2011-06-22 05:22:12 UTC</tt>.<br>
: This revision was by author [[User:xenwolf|xenwolf]] and made on <tt>2011-06-30 16:18:29 UTC</tt>.<br>
: The original revision id was <tt>238134791</tt>.<br>
: The original revision id was <tt>239550315</tt>.<br>
: The revision comment was: <tt></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>
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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=Basic properties=  
=Basic properties=  
28edo, a multiple of both 7edo and 14edo, has a step size of 42.86 cents. It shares three intervals with 12edo: the 300 cent minor third, the 600 cent tritone, and the 900 cent major sixth. Thus it tempers out the greater diesis 648:625. It does not however temper out the 128:125 lesser diesis, as its major third is less than 1 cent flat (and its inversion the minor sixth less than 1 cent sharp). It has the same perfect fourth and fifth as 14edo. It also has decent approximations of several septimal intervals, of which 9/7 and its inversion 14/9 are also found in 14edo.
28edo, a multiple of both [[7edo]] and [[14edo]] (and of course [[2edo]] and [[4edo]]), has a step size of 42.857 [[cent]]s. It shares three intervals with [[12edo]]: the 300 cent minor third, the 600 cent tritone, and the 900 cent major sixth. Thus it [[tempering out|tempers out]] the [[greater diesis]] [[648_625|648:625]]. It does not however temper out the [[128_125|128:125]] [[lesser diesis]], as its major third is less than 1 cent flat (and its inversion the minor sixth less than 1 cent sharp). It has the same perfect fourth and fifth as 14edo. It also has decent approximations of several septimal intervals, of which [[9_7|9/7]] and its inversion [[14_9|14/9]] are also found in 14edo.


=Subgroups=  
=Subgroups=  
28edo can approximate the 7-limit subgroup 2.27.5.21 quite well, and on this subgroup it has the same commas and tunings as 84edo. The temperament corresponding to [[Semicomma family|orwell temperament]] now has a major third as generator, though as before 225/224, 1728/1715 and 6144/6125 are tempered out. The 225/224-tempered version of the [[augmented triad]] has a very low complexity, so many of them appear in the MOS scales for this temperament, which have sizes 7, 10, 13, 16, 19, 22, 25.
28edo can approximate the [[7-limit]] subgroup 2.27.5.21 quite well, and on this subgroup it has the same commas and tunings as 84edo. The temperament corresponding to [[Semicomma family|orwell temperament]] now has a major third as generator, though as before 225/224, 1728/1715 and 6144/6125 are tempered out. The 225/224-tempered version of the [[augmented triad]] has a very low complexity, so many of them appear in the [[MOS scales]] for this temperament, which have sizes 7, 10, 13, 16, 19, 22, 25.


=Table of intervals=  
=Table of intervals=  
The following table compares it to potentially useful nearby just intervals.
The following table compares it to potentially useful nearby [[just intervals]].


|| Step # || ET Cents || Just Interval || Just Cents || Difference (ET minus Just) ||
|| Step # || ET Cents || Just Interval || Just Cents || Difference (ET minus Just) ||
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|| 28 || 1200 || 2:1 || 1200 || 0 ||
|| 28 || 1200 || 2:1 || 1200 || 0 ||
=Commas=  
=Commas=  
28 EDO tempers out the following commas. (Note: This assumes the val &lt; 28 44 65 79 97 104 |.)
28 EDO tempers out the following [[comma]]s. (Note: This assumes the val &lt; 28 44 65 79 97 104 |.)
||~ Comma ||~ Monzo ||~ Value (Cents) ||~ Name 1 ||~ Name 2 ||
||~ Comma ||~ Monzo ||~ Value (Cents) ||~ Name 1 ||~ Name 2 ||
||= 2187/2048 || | -11 7 &gt; ||&gt; 113.69 ||= Apotome ||=  ||
||= 2187/2048 || | -11 7 &gt; ||&gt; 113.69 ||= Apotome ||=  ||
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&lt;br /&gt;
&lt;br /&gt;
&lt;!-- ws:start:WikiTextHeadingRule:0:&amp;lt;h1&amp;gt; --&gt;&lt;h1 id="toc0"&gt;&lt;a name="Basic properties"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:0 --&gt;Basic properties&lt;/h1&gt;
&lt;!-- ws:start:WikiTextHeadingRule:0:&amp;lt;h1&amp;gt; --&gt;&lt;h1 id="toc0"&gt;&lt;a name="Basic properties"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:0 --&gt;Basic properties&lt;/h1&gt;
  28edo, a multiple of both 7edo and 14edo, has a step size of 42.86 cents. It shares three intervals with 12edo: the 300 cent minor third, the 600 cent tritone, and the 900 cent major sixth. Thus it tempers out the greater diesis 648:625. It does not however temper out the 128:125 lesser diesis, as its major third is less than 1 cent flat (and its inversion the minor sixth less than 1 cent sharp). It has the same perfect fourth and fifth as 14edo. It also has decent approximations of several septimal intervals, of which 9/7 and its inversion 14/9 are also found in 14edo.&lt;br /&gt;
  28edo, a multiple of both &lt;a class="wiki_link" href="/7edo"&gt;7edo&lt;/a&gt; and &lt;a class="wiki_link" href="/14edo"&gt;14edo&lt;/a&gt; (and of course &lt;a class="wiki_link" href="/2edo"&gt;2edo&lt;/a&gt; and &lt;a class="wiki_link" href="/4edo"&gt;4edo&lt;/a&gt;), has a step size of 42.857 &lt;a class="wiki_link" href="/cent"&gt;cent&lt;/a&gt;s. It shares three intervals with &lt;a class="wiki_link" href="/12edo"&gt;12edo&lt;/a&gt;: the 300 cent minor third, the 600 cent tritone, and the 900 cent major sixth. Thus it &lt;a class="wiki_link" href="/tempering%20out"&gt;tempers out&lt;/a&gt; the &lt;a class="wiki_link" href="/greater%20diesis"&gt;greater diesis&lt;/a&gt; &lt;a class="wiki_link" href="/648_625"&gt;648:625&lt;/a&gt;. It does not however temper out the &lt;a class="wiki_link" href="/128_125"&gt;128:125&lt;/a&gt; &lt;a class="wiki_link" href="/lesser%20diesis"&gt;lesser diesis&lt;/a&gt;, as its major third is less than 1 cent flat (and its inversion the minor sixth less than 1 cent sharp). It has the same perfect fourth and fifth as 14edo. It also has decent approximations of several septimal intervals, of which &lt;a class="wiki_link" href="/9_7"&gt;9/7&lt;/a&gt; and its inversion &lt;a class="wiki_link" href="/14_9"&gt;14/9&lt;/a&gt; are also found in 14edo.&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
&lt;!-- ws:start:WikiTextHeadingRule:2:&amp;lt;h1&amp;gt; --&gt;&lt;h1 id="toc1"&gt;&lt;a name="Subgroups"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:2 --&gt;Subgroups&lt;/h1&gt;
&lt;!-- ws:start:WikiTextHeadingRule:2:&amp;lt;h1&amp;gt; --&gt;&lt;h1 id="toc1"&gt;&lt;a name="Subgroups"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:2 --&gt;Subgroups&lt;/h1&gt;
  28edo can approximate the 7-limit subgroup 2.27.5.21 quite well, and on this subgroup it has the same commas and tunings as 84edo. The temperament corresponding to &lt;a class="wiki_link" href="/Semicomma%20family"&gt;orwell temperament&lt;/a&gt; now has a major third as generator, though as before 225/224, 1728/1715 and 6144/6125 are tempered out. The 225/224-tempered version of the &lt;a class="wiki_link" href="/augmented%20triad"&gt;augmented triad&lt;/a&gt; has a very low complexity, so many of them appear in the MOS scales for this temperament, which have sizes 7, 10, 13, 16, 19, 22, 25.&lt;br /&gt;
  28edo can approximate the &lt;a class="wiki_link" href="/7-limit"&gt;7-limit&lt;/a&gt; subgroup 2.27.5.21 quite well, and on this subgroup it has the same commas and tunings as 84edo. The temperament corresponding to &lt;a class="wiki_link" href="/Semicomma%20family"&gt;orwell temperament&lt;/a&gt; now has a major third as generator, though as before 225/224, 1728/1715 and 6144/6125 are tempered out. The 225/224-tempered version of the &lt;a class="wiki_link" href="/augmented%20triad"&gt;augmented triad&lt;/a&gt; has a very low complexity, so many of them appear in the &lt;a class="wiki_link" href="/MOS%20scales"&gt;MOS scales&lt;/a&gt; for this temperament, which have sizes 7, 10, 13, 16, 19, 22, 25.&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
&lt;!-- ws:start:WikiTextHeadingRule:4:&amp;lt;h1&amp;gt; --&gt;&lt;h1 id="toc2"&gt;&lt;a name="Table of intervals"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:4 --&gt;Table of intervals&lt;/h1&gt;
&lt;!-- ws:start:WikiTextHeadingRule:4:&amp;lt;h1&amp;gt; --&gt;&lt;h1 id="toc2"&gt;&lt;a name="Table of intervals"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:4 --&gt;Table of intervals&lt;/h1&gt;
  The following table compares it to potentially useful nearby just intervals.&lt;br /&gt;
  The following table compares it to potentially useful nearby &lt;a class="wiki_link" href="/just%20intervals"&gt;just intervals&lt;/a&gt;.&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;


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&lt;!-- ws:start:WikiTextHeadingRule:6:&amp;lt;h1&amp;gt; --&gt;&lt;h1 id="toc3"&gt;&lt;a name="Commas"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:6 --&gt;Commas&lt;/h1&gt;
&lt;!-- ws:start:WikiTextHeadingRule:6:&amp;lt;h1&amp;gt; --&gt;&lt;h1 id="toc3"&gt;&lt;a name="Commas"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:6 --&gt;Commas&lt;/h1&gt;
  28 EDO tempers out the following commas. (Note: This assumes the val &amp;lt; 28 44 65 79 97 104 |.)&lt;br /&gt;
  28 EDO tempers out the following &lt;a class="wiki_link" href="/comma"&gt;comma&lt;/a&gt;s. (Note: This assumes the val &amp;lt; 28 44 65 79 97 104 |.)&lt;br /&gt;