27edo

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Revision as of 22:25, 31 May 2011 by Wikispaces>jdfreivald (**Imported revision 233349542 - Original comment: Added comma table.**)
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This revision was by author jdfreivald and made on 2011-05-31 22:25:14 UTC.
The original revision id was 233349542.
The revision comment was: Added comma table.

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Original Wikitext content:

=<span style="color: #0061ff; font-size: 103%;">27 tone equal tempertament</span>= 

If octaves are kept pure, 27edo divides the octave in 27 equal parts each exactly 44.444... cents in size. However, 27 is a prime candidate for octave shrinking, and a step size of 44.3 to 44.35 cents would be reasonable. The reason for this is that 27edo tunes the third, fifth and 7/4 sharply.

Assuming however pure octaves, 27 has a fifth sharp by slightly more than nine cents and a 7/4 sharp by slightly less, and the same 400 cent major third as 12edo, sharp 13 2/3 cents. The result is that 6/5, 7/5 and especially 7/6 are all tuned more accurately than this.

27edo, with its 400 cent major third, tempers out the diesis of 128/125, and also the septimal comma, 64/63 (and hence 126/125 also.) These it shares with 12edo, making some relationships familiar, and as a consequence they both support augene temperament. It shares with 22edo tempering out 245/243 (allegedly a Bohlen-Pierce comma, yet hear it turns up anyway) as well as 64/63, so that they both support superpyth temperament, with quite sharp "superpythagorean" fifths giving a sharp
9/7 in place of meantone's 5/4.

==Intervals== 
|| Degrees of 27-EDO || Cents value ||
|| 0 || 0 ||
|| 1 || 44,44 ||
|| 2 || 88,89 ||
|| 3 || 133,33 ||
|| 4 || 177,78 ||
|| 5 || 222,22 ||
|| 6 || 266,67 ||
|| 7 || 311,11 ||
|| 8 || 355,56 ||
|| 9 || 400 ||
|| 10 || 444,44 ||
|| 11 || 488,89 ||
|| 12 || 533,33 ||
|| 13 || 577,78 ||
|| 14 || 622,22 ||
|| 15 || 666,67 ||
|| 16 || 711,11 ||
|| 17 || 755,56 ||
|| 18 || 800 ||
|| 19 || 844,44 ||
|| 20 || 888,89 ||
|| 21 || 933,33 ||
|| 22 || 977,78 ||
|| 23 || 1022,22 ||
|| 24 || 1066,67 ||
|| 25 || 1111,11 ||
|| 26 || 1155,56 ||
==Commas== 
27 EDO tempers out the following commas. (Note: This assumes the val < 27 43 63 76 93 100 |.)
||~ Comma ||~ Monzo ||~ Value (Cents) ||~ Name 1 ||~ Name 2 ||~ Name 3 ||
|| 128/125 || | 7 0 -3 > || 41.06 || Diesis || Augmented Comma ||   ||
|| 20000/19683 || | 5 -9 4 > || 27.66 || Minimal Diesis || Tetracot Comma ||   ||
|| 78732/78125 || | 2 9 -7 > || 13.40 || Medium Semicomma || Sensipent Comma ||   ||
|| 4711802/4709457 || | 1 -27 18 > || 0.86 || Ennealimma ||   ||   ||
|| 686/675 || | 1 -3 -2 3 > || 27.99 || Senga ||   ||   ||
|| 64/63 || | 6 -2 0 -1 > || 27.26 || Septimal Comma || Archytas' Comma || Leipziger Komma ||
|| 50421/50000 || | -4 1 -5 5 > || 14.52 || Trimyna ||   ||   ||
|| 245/243 || | 0 -5 1 2 > || 14.19 || Sensamagic ||   ||   ||
|| 126/125 || | 1 2 -3 1 > || 13.79 || Septimal Semicomma || Starling Comma ||   ||
|| 4000/3969 || | 5 -4 3 -2 > || 13.47 || Octagar ||   ||   ||
|| 1728/1715 || | 6 3 -1 -3 > || 13.07 || Orwellisma || Orwell Comma ||   ||
|| 420175/419904 || | -6 -8 2 5 > || 1.12 || Wizma ||   ||   ||
|| 2401/2400 || | -5 -1 -2 4 > || 0.72 || Breedsma ||   ||   ||
|| 4375/4374 || | -1 -7 4 1 > || 0.40 || Ragisma ||   ||   ||
|| 250047/250000 || | -4 6 -6 3 > || 0.33 || Landscape Comma ||   ||   ||
|| 99/98 || | -1 2 0 -2 1 > || 17.58 || Mothwellsma ||   ||   ||
|| 896/891 || | 7 -4 0 1 -1 > || 9.69 || Pentacircle ||   ||   ||
|| 385/384 || | -7 -1 1 1 1 > || 4.50 || Keenanisma ||   ||   ||
|| 91/90 || | -1 -2 -1 1 0 1 > || 19.13 || Superleap ||   ||   ||

<span style="display: block; height: 1px; left: -10000px; overflow: hidden; position: absolute; top: 705px; width: 1px;">
|| < 27 43 63 76 93 100 | ||
</span>

Original HTML content:

<html><head><title>27edo</title></head><body><!-- ws:start:WikiTextHeadingRule:0:&lt;h1&gt; --><h1 id="toc0"><a name="x27 tone equal tempertament"></a><!-- ws:end:WikiTextHeadingRule:0 --><span style="color: #0061ff; font-size: 103%;">27 tone equal tempertament</span></h1>
 <br />
If octaves are kept pure, 27edo divides the octave in 27 equal parts each exactly 44.444... cents in size. However, 27 is a prime candidate for octave shrinking, and a step size of 44.3 to 44.35 cents would be reasonable. The reason for this is that 27edo tunes the third, fifth and 7/4 sharply.<br />
<br />
Assuming however pure octaves, 27 has a fifth sharp by slightly more than nine cents and a 7/4 sharp by slightly less, and the same 400 cent major third as 12edo, sharp 13 2/3 cents. The result is that 6/5, 7/5 and especially 7/6 are all tuned more accurately than this.<br />
<br />
27edo, with its 400 cent major third, tempers out the diesis of 128/125, and also the septimal comma, 64/63 (and hence 126/125 also.) These it shares with 12edo, making some relationships familiar, and as a consequence they both support augene temperament. It shares with 22edo tempering out 245/243 (allegedly a Bohlen-Pierce comma, yet hear it turns up anyway) as well as 64/63, so that they both support superpyth temperament, with quite sharp &quot;superpythagorean&quot; fifths giving a sharp<br />
9/7 in place of meantone's 5/4.<br />
<br />
<!-- ws:start:WikiTextHeadingRule:2:&lt;h2&gt; --><h2 id="toc1"><a name="x27 tone equal tempertament-Intervals"></a><!-- ws:end:WikiTextHeadingRule:2 -->Intervals</h2>
 

<table class="wiki_table">
    <tr>
        <td>Degrees of 27-EDO<br />
</td>
        <td>Cents value<br />
</td>
    </tr>
    <tr>
        <td>0<br />
</td>
        <td>0<br />
</td>
    </tr>
    <tr>
        <td>1<br />
</td>
        <td>44,44<br />
</td>
    </tr>
    <tr>
        <td>2<br />
</td>
        <td>88,89<br />
</td>
    </tr>
    <tr>
        <td>3<br />
</td>
        <td>133,33<br />
</td>
    </tr>
    <tr>
        <td>4<br />
</td>
        <td>177,78<br />
</td>
    </tr>
    <tr>
        <td>5<br />
</td>
        <td>222,22<br />
</td>
    </tr>
    <tr>
        <td>6<br />
</td>
        <td>266,67<br />
</td>
    </tr>
    <tr>
        <td>7<br />
</td>
        <td>311,11<br />
</td>
    </tr>
    <tr>
        <td>8<br />
</td>
        <td>355,56<br />
</td>
    </tr>
    <tr>
        <td>9<br />
</td>
        <td>400<br />
</td>
    </tr>
    <tr>
        <td>10<br />
</td>
        <td>444,44<br />
</td>
    </tr>
    <tr>
        <td>11<br />
</td>
        <td>488,89<br />
</td>
    </tr>
    <tr>
        <td>12<br />
</td>
        <td>533,33<br />
</td>
    </tr>
    <tr>
        <td>13<br />
</td>
        <td>577,78<br />
</td>
    </tr>
    <tr>
        <td>14<br />
</td>
        <td>622,22<br />
</td>
    </tr>
    <tr>
        <td>15<br />
</td>
        <td>666,67<br />
</td>
    </tr>
    <tr>
        <td>16<br />
</td>
        <td>711,11<br />
</td>
    </tr>
    <tr>
        <td>17<br />
</td>
        <td>755,56<br />
</td>
    </tr>
    <tr>
        <td>18<br />
</td>
        <td>800<br />
</td>
    </tr>
    <tr>
        <td>19<br />
</td>
        <td>844,44<br />
</td>
    </tr>
    <tr>
        <td>20<br />
</td>
        <td>888,89<br />
</td>
    </tr>
    <tr>
        <td>21<br />
</td>
        <td>933,33<br />
</td>
    </tr>
    <tr>
        <td>22<br />
</td>
        <td>977,78<br />
</td>
    </tr>
    <tr>
        <td>23<br />
</td>
        <td>1022,22<br />
</td>
    </tr>
    <tr>
        <td>24<br />
</td>
        <td>1066,67<br />
</td>
    </tr>
    <tr>
        <td>25<br />
</td>
        <td>1111,11<br />
</td>
    </tr>
    <tr>
        <td>26<br />
</td>
        <td>1155,56<br />
</td>
    </tr>
</table>

<!-- ws:start:WikiTextHeadingRule:4:&lt;h2&gt; --><h2 id="toc2"><a name="x27 tone equal tempertament-Commas"></a><!-- ws:end:WikiTextHeadingRule:4 -->Commas</h2>
 27 EDO tempers out the following commas. (Note: This assumes the val &lt; 27 43 63 76 93 100 |.)<br />


<table class="wiki_table">
    <tr>
        <th>Comma<br />
</th>
        <th>Monzo<br />
</th>
        <th>Value (Cents)<br />
</th>
        <th>Name 1<br />
</th>
        <th>Name 2<br />
</th>
        <th>Name 3<br />
</th>
    </tr>
    <tr>
        <td>128/125<br />
</td>
        <td>| 7 0 -3 &gt;<br />
</td>
        <td>41.06<br />
</td>
        <td>Diesis<br />
</td>
        <td>Augmented Comma<br />
</td>
        <td><br />
</td>
    </tr>
    <tr>
        <td>20000/19683<br />
</td>
        <td>| 5 -9 4 &gt;<br />
</td>
        <td>27.66<br />
</td>
        <td>Minimal Diesis<br />
</td>
        <td>Tetracot Comma<br />
</td>
        <td><br />
</td>
    </tr>
    <tr>
        <td>78732/78125<br />
</td>
        <td>| 2 9 -7 &gt;<br />
</td>
        <td>13.40<br />
</td>
        <td>Medium Semicomma<br />
</td>
        <td>Sensipent Comma<br />
</td>
        <td><br />
</td>
    </tr>
    <tr>
        <td>4711802/4709457<br />
</td>
        <td>| 1 -27 18 &gt;<br />
</td>
        <td>0.86<br />
</td>
        <td>Ennealimma<br />
</td>
        <td><br />
</td>
        <td><br />
</td>
    </tr>
    <tr>
        <td>686/675<br />
</td>
        <td>| 1 -3 -2 3 &gt;<br />
</td>
        <td>27.99<br />
</td>
        <td>Senga<br />
</td>
        <td><br />
</td>
        <td><br />
</td>
    </tr>
    <tr>
        <td>64/63<br />
</td>
        <td>| 6 -2 0 -1 &gt;<br />
</td>
        <td>27.26<br />
</td>
        <td>Septimal Comma<br />
</td>
        <td>Archytas' Comma<br />
</td>
        <td>Leipziger Komma<br />
</td>
    </tr>
    <tr>
        <td>50421/50000<br />
</td>
        <td>| -4 1 -5 5 &gt;<br />
</td>
        <td>14.52<br />
</td>
        <td>Trimyna<br />
</td>
        <td><br />
</td>
        <td><br />
</td>
    </tr>
    <tr>
        <td>245/243<br />
</td>
        <td>| 0 -5 1 2 &gt;<br />
</td>
        <td>14.19<br />
</td>
        <td>Sensamagic<br />
</td>
        <td><br />
</td>
        <td><br />
</td>
    </tr>
    <tr>
        <td>126/125<br />
</td>
        <td>| 1 2 -3 1 &gt;<br />
</td>
        <td>13.79<br />
</td>
        <td>Septimal Semicomma<br />
</td>
        <td>Starling Comma<br />
</td>
        <td><br />
</td>
    </tr>
    <tr>
        <td>4000/3969<br />
</td>
        <td>| 5 -4 3 -2 &gt;<br />
</td>
        <td>13.47<br />
</td>
        <td>Octagar<br />
</td>
        <td><br />
</td>
        <td><br />
</td>
    </tr>
    <tr>
        <td>1728/1715<br />
</td>
        <td>| 6 3 -1 -3 &gt;<br />
</td>
        <td>13.07<br />
</td>
        <td>Orwellisma<br />
</td>
        <td>Orwell Comma<br />
</td>
        <td><br />
</td>
    </tr>
    <tr>
        <td>420175/419904<br />
</td>
        <td>| -6 -8 2 5 &gt;<br />
</td>
        <td>1.12<br />
</td>
        <td>Wizma<br />
</td>
        <td><br />
</td>
        <td><br />
</td>
    </tr>
    <tr>
        <td>2401/2400<br />
</td>
        <td>| -5 -1 -2 4 &gt;<br />
</td>
        <td>0.72<br />
</td>
        <td>Breedsma<br />
</td>
        <td><br />
</td>
        <td><br />
</td>
    </tr>
    <tr>
        <td>4375/4374<br />
</td>
        <td>| -1 -7 4 1 &gt;<br />
</td>
        <td>0.40<br />
</td>
        <td>Ragisma<br />
</td>
        <td><br />
</td>
        <td><br />
</td>
    </tr>
    <tr>
        <td>250047/250000<br />
</td>
        <td>| -4 6 -6 3 &gt;<br />
</td>
        <td>0.33<br />
</td>
        <td>Landscape Comma<br />
</td>
        <td><br />
</td>
        <td><br />
</td>
    </tr>
    <tr>
        <td>99/98<br />
</td>
        <td>| -1 2 0 -2 1 &gt;<br />
</td>
        <td>17.58<br />
</td>
        <td>Mothwellsma<br />
</td>
        <td><br />
</td>
        <td><br />
</td>
    </tr>
    <tr>
        <td>896/891<br />
</td>
        <td>| 7 -4 0 1 -1 &gt;<br />
</td>
        <td>9.69<br />
</td>
        <td>Pentacircle<br />
</td>
        <td><br />
</td>
        <td><br />
</td>
    </tr>
    <tr>
        <td>385/384<br />
</td>
        <td>| -7 -1 1 1 1 &gt;<br />
</td>
        <td>4.50<br />
</td>
        <td>Keenanisma<br />
</td>
        <td><br />
</td>
        <td><br />
</td>
    </tr>
    <tr>
        <td>91/90<br />
</td>
        <td>| -1 -2 -1 1 0 1 &gt;<br />
</td>
        <td>19.13<br />
</td>
        <td>Superleap<br />
</td>
        <td><br />
</td>
        <td><br />
</td>
    </tr>
</table>

<br />
<span style="display: block; height: 1px; left: -10000px; overflow: hidden; position: absolute; top: 705px; width: 1px;"><br />


<table class="wiki_table">
    <tr>
        <td>&lt; 27 43 63 76 93 100 |<br />
</td>
    </tr>
</table>

</span></body></html>