28edo: Difference between revisions
Wikispaces>hstraub **Imported revision 238134791 - Original comment: ** |
Wikispaces>xenwolf **Imported revision 239550315 - Original comment: ** |
||
Line 1: | Line 1: | ||
<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: | : 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> | : 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> | ||
Line 10: | Line 10: | ||
=Basic properties= | =Basic properties= | ||
28edo, a multiple of both 7edo and 14edo, has a step size of 42. | 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) || | ||
Line 49: | Line 49: | ||
|| 28 || 1200 || 2:1 || 1200 || 0 || | || 28 || 1200 || 2:1 || 1200 || 0 || | ||
=Commas= | =Commas= | ||
28 EDO tempers out the following | 28 EDO tempers out the following [[comma]]s. (Note: This assumes the val < 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 > ||> 113.69 ||= Apotome ||= || | ||= 2187/2048 || | -11 7 > ||> 113.69 ||= Apotome ||= || | ||
Line 74: | Line 74: | ||
<br /> | <br /> | ||
<!-- ws:start:WikiTextHeadingRule:0:&lt;h1&gt; --><h1 id="toc0"><a name="Basic properties"></a><!-- ws:end:WikiTextHeadingRule:0 -->Basic properties</h1> | <!-- ws:start:WikiTextHeadingRule:0:&lt;h1&gt; --><h1 id="toc0"><a name="Basic properties"></a><!-- ws:end:WikiTextHeadingRule:0 -->Basic properties</h1> | ||
28edo, a multiple of both 7edo and 14edo, has a step size of 42. | 28edo, a multiple of both <a class="wiki_link" href="/7edo">7edo</a> and <a class="wiki_link" href="/14edo">14edo</a> (and of course <a class="wiki_link" href="/2edo">2edo</a> and <a class="wiki_link" href="/4edo">4edo</a>), has a step size of 42.857 <a class="wiki_link" href="/cent">cent</a>s. It shares three intervals with <a class="wiki_link" href="/12edo">12edo</a>: the 300 cent minor third, the 600 cent tritone, and the 900 cent major sixth. Thus it <a class="wiki_link" href="/tempering%20out">tempers out</a> the <a class="wiki_link" href="/greater%20diesis">greater diesis</a> <a class="wiki_link" href="/648_625">648:625</a>. It does not however temper out the <a class="wiki_link" href="/128_125">128:125</a> <a class="wiki_link" href="/lesser%20diesis">lesser diesis</a>, 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 <a class="wiki_link" href="/9_7">9/7</a> and its inversion <a class="wiki_link" href="/14_9">14/9</a> are also found in 14edo.<br /> | ||
<br /> | <br /> | ||
<!-- ws:start:WikiTextHeadingRule:2:&lt;h1&gt; --><h1 id="toc1"><a name="Subgroups"></a><!-- ws:end:WikiTextHeadingRule:2 -->Subgroups</h1> | <!-- ws:start:WikiTextHeadingRule:2:&lt;h1&gt; --><h1 id="toc1"><a name="Subgroups"></a><!-- ws:end:WikiTextHeadingRule:2 -->Subgroups</h1> | ||
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 <a class="wiki_link" href="/Semicomma%20family">orwell temperament</a> 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 <a class="wiki_link" href="/augmented%20triad">augmented triad</a> 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.<br /> | 28edo can approximate the <a class="wiki_link" href="/7-limit">7-limit</a> subgroup 2.27.5.21 quite well, and on this subgroup it has the same commas and tunings as 84edo. The temperament corresponding to <a class="wiki_link" href="/Semicomma%20family">orwell temperament</a> 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 <a class="wiki_link" href="/augmented%20triad">augmented triad</a> has a very low complexity, so many of them appear in the <a class="wiki_link" href="/MOS%20scales">MOS scales</a> for this temperament, which have sizes 7, 10, 13, 16, 19, 22, 25.<br /> | ||
<br /> | <br /> | ||
<!-- ws:start:WikiTextHeadingRule:4:&lt;h1&gt; --><h1 id="toc2"><a name="Table of intervals"></a><!-- ws:end:WikiTextHeadingRule:4 -->Table of intervals</h1> | <!-- ws:start:WikiTextHeadingRule:4:&lt;h1&gt; --><h1 id="toc2"><a name="Table of intervals"></a><!-- ws:end:WikiTextHeadingRule:4 -->Table of intervals</h1> | ||
The following table compares it to potentially useful nearby just intervals.<br /> | The following table compares it to potentially useful nearby <a class="wiki_link" href="/just%20intervals">just intervals</a>.<br /> | ||
<br /> | <br /> | ||
Line 448: | Line 448: | ||
<!-- ws:start:WikiTextHeadingRule:6:&lt;h1&gt; --><h1 id="toc3"><a name="Commas"></a><!-- ws:end:WikiTextHeadingRule:6 -->Commas</h1> | <!-- ws:start:WikiTextHeadingRule:6:&lt;h1&gt; --><h1 id="toc3"><a name="Commas"></a><!-- ws:end:WikiTextHeadingRule:6 -->Commas</h1> | ||
28 EDO tempers out the following | 28 EDO tempers out the following <a class="wiki_link" href="/comma">comma</a>s. (Note: This assumes the val &lt; 28 44 65 79 97 104 |.)<br /> | ||