18edo: Difference between revisions

Wikispaces>xenwolf
**Imported revision 139248817 - Original comment: simplified structure :-) Are there any good examples for listening?**
Wikispaces>guest
**Imported revision 147555503 - 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:xenwolf|xenwolf]] and made on <tt>2010-05-04 03:31:43 UTC</tt>.<br>
: This revision was by author [[User:guest|guest]] and made on <tt>2010-06-07 23:02:15 UTC</tt>.<br>
: The original revision id was <tt>139248817</tt>.<br>
: The original revision id was <tt>147555503</tt>.<br>
: The revision comment was: <tt>simplified structure :-) Are there any good examples for listening?</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>
<h4>Original Wikitext content:</h4>
<h4>Original Wikitext content:</h4>
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AKA The Third-Tone System
AKA The Third-Tone System
==Basic Properties==  
==Basic Properties==  
=== Representations of Just Intervals ===
===Representations of Just Intervals===  
|| Degree || Cents || Nearest Ratio || Error (cents) ||
|| Degree || Cents || Nearest Ratio || Error (cents) ||
|| 0 || 0 || 1/1 || 0 ||
|| 0 || 0 || 1/1 || 0 ||
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18-EDO does not approximate the 3rd Harmonic at all, unless a &gt;30¢-error is considered acceptable. This makes it unsuitable for rendering common-practice music. However, it does offer excellent approximations of 27/25, 9/8, 7/6, 17/14, 21/16, and 15/11 (and their respective reciprocal intervals), so it is still capable of playing consonant music; however, in order to access these consonances, one must take a considerably "non-common-practice" approach.
18-EDO does not approximate the 3rd Harmonic at all, unless a &gt;30¢-error is considered acceptable. This makes it unsuitable for rendering common-practice music. However, it does offer excellent approximations of 27/25, 9/8, 7/6, 17/14, 21/16, and 15/11 (and their respective reciprocal intervals), so it is still capable of playing consonant music; however, in order to access these consonances, one must take a considerably "non-common-practice" approach.


=== Relationship to Other EDOs ===
===Relationship to Other EDOs===  
18-EDO, aka the "third-tone" system, is related to [[12edo|12-tET]] by the whole-tone scale (which is [[6edo|6-EDO]]), since 18=6*3 and 12=6*2; hence a 12-tET "whole tone" is divided into 3 equal parts in 18-EDO. Since 18=9*2, 18-EDO contains two sets of [[9edo|9-EDO]], offset from each other by a third-tone. 18-EDO is related to [[13edo|13-EDO]], [[21edo|21-EDO]], [[23edo|23-EDO]], and [[28edo|28-EDO]] in that all are [[Father Temperament|"Father" temperaments]] (they temper out 16/15--the difference between a major third and perfect fourth). It is related to [[11edo|11-EDO]], [[15edo|15-EDO]], [[25edo|25-EDO]], and [[19edo|29-EDO]] in that they are all [[Amity Temperament|"Amity" temperaments]] ("Amity" is derived from the acronym of "Acute Minor Thirds", meaning a minor third sharper than 6/5 but still flatter than a neutral third).
18-EDO, aka the "third-tone" system, is related to [[12edo|12-tET]] by the whole-tone scale (which is [[6edo|6-EDO]]), since 18=6*3 and 12=6*2; hence a 12-tET "whole tone" is divided into 3 equal parts in 18-EDO. Since 18=9*2, 18-EDO contains two sets of [[9edo|9-EDO]], offset from each other by a third-tone. 18-EDO is related to [[13edo|13-EDO]], [[21edo|21-EDO]], [[23edo|23-EDO]], and [[28edo|28-EDO]] in that all are [[Father Temperament|"Father" temperaments]] (they temper out 16/15--the difference between a major third and perfect fourth). It is related to [[11edo|11-EDO]], [[15edo|15-EDO]], [[25edo|25-EDO]], and 29-EDO in that they are all [[Amity Temperament|"Amity" temperaments]] ("Amity" is derived from the acronym of "Acute Minor Thirds", meaning a minor third sharper than 6/5 but still flatter than a neutral third).


==Useful Moment-of-Symmetry Scales==  
==Useful Moment-of-Symmetry Scales==  
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  AKA The Third-Tone System&lt;br /&gt;
  AKA The Third-Tone System&lt;br /&gt;
&lt;!-- ws:start:WikiTextHeadingRule:2:&amp;lt;h2&amp;gt; --&gt;&lt;h2 id="toc1"&gt;&lt;a name="x18 Equal Divisions of the Octave-Basic Properties"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:2 --&gt;Basic Properties&lt;/h2&gt;
&lt;!-- ws:start:WikiTextHeadingRule:2:&amp;lt;h2&amp;gt; --&gt;&lt;h2 id="toc1"&gt;&lt;a name="x18 Equal Divisions of the Octave-Basic Properties"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:2 --&gt;Basic Properties&lt;/h2&gt;
  &lt;!-- ws:start:WikiTextHeadingRule:4:&amp;lt;h3&amp;gt; --&gt;&lt;h3 id="toc2"&gt;&lt;a name="x18 Equal Divisions of the Octave-Basic Properties-Representations of Just Intervals"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:4 --&gt; Representations of Just Intervals &lt;/h3&gt;
  &lt;!-- ws:start:WikiTextHeadingRule:4:&amp;lt;h3&amp;gt; --&gt;&lt;h3 id="toc2"&gt;&lt;a name="x18 Equal Divisions of the Octave-Basic Properties-Representations of Just Intervals"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:4 --&gt;Representations of Just Intervals&lt;/h3&gt;
 


&lt;table class="wiki_table"&gt;
&lt;table class="wiki_table"&gt;
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18-EDO does not approximate the 3rd Harmonic at all, unless a &amp;gt;30¢-error is considered acceptable. This makes it unsuitable for rendering common-practice music. However, it does offer excellent approximations of 27/25, 9/8, 7/6, 17/14, 21/16, and 15/11 (and their respective reciprocal intervals), so it is still capable of playing consonant music; however, in order to access these consonances, one must take a considerably &amp;quot;non-common-practice&amp;quot; approach.&lt;br /&gt;
18-EDO does not approximate the 3rd Harmonic at all, unless a &amp;gt;30¢-error is considered acceptable. This makes it unsuitable for rendering common-practice music. However, it does offer excellent approximations of 27/25, 9/8, 7/6, 17/14, 21/16, and 15/11 (and their respective reciprocal intervals), so it is still capable of playing consonant music; however, in order to access these consonances, one must take a considerably &amp;quot;non-common-practice&amp;quot; approach.&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
&lt;!-- ws:start:WikiTextHeadingRule:6:&amp;lt;h3&amp;gt; --&gt;&lt;h3 id="toc3"&gt;&lt;a name="x18 Equal Divisions of the Octave-Basic Properties-Relationship to Other EDOs"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:6 --&gt; Relationship to Other EDOs &lt;/h3&gt;
&lt;!-- ws:start:WikiTextHeadingRule:6:&amp;lt;h3&amp;gt; --&gt;&lt;h3 id="toc3"&gt;&lt;a name="x18 Equal Divisions of the Octave-Basic Properties-Relationship to Other EDOs"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:6 --&gt;Relationship to Other EDOs&lt;/h3&gt;
18-EDO, aka the &amp;quot;third-tone&amp;quot; system, is related to &lt;a class="wiki_link" href="/12edo"&gt;12-tET&lt;/a&gt; by the whole-tone scale (which is &lt;a class="wiki_link" href="/6edo"&gt;6-EDO&lt;/a&gt;), since 18=6*3 and 12=6*2; hence a 12-tET &amp;quot;whole tone&amp;quot; is divided into 3 equal parts in 18-EDO. Since 18=9*2, 18-EDO contains two sets of &lt;a class="wiki_link" href="/9edo"&gt;9-EDO&lt;/a&gt;, offset from each other by a third-tone. 18-EDO is related to &lt;a class="wiki_link" href="/13edo"&gt;13-EDO&lt;/a&gt;, &lt;a class="wiki_link" href="/21edo"&gt;21-EDO&lt;/a&gt;, &lt;a class="wiki_link" href="/23edo"&gt;23-EDO&lt;/a&gt;, and &lt;a class="wiki_link" href="/28edo"&gt;28-EDO&lt;/a&gt; in that all are &lt;a class="wiki_link" href="/Father%20Temperament"&gt;&amp;quot;Father&amp;quot; temperaments&lt;/a&gt; (they temper out 16/15--the difference between a major third and perfect fourth). It is related to &lt;a class="wiki_link" href="/11edo"&gt;11-EDO&lt;/a&gt;, &lt;a class="wiki_link" href="/15edo"&gt;15-EDO&lt;/a&gt;, &lt;a class="wiki_link" href="/25edo"&gt;25-EDO&lt;/a&gt;, and &lt;a class="wiki_link" href="/19edo"&gt;29-EDO&lt;/a&gt; in that they are all &lt;a class="wiki_link" href="/Amity%20Temperament"&gt;&amp;quot;Amity&amp;quot; temperaments&lt;/a&gt; (&amp;quot;Amity&amp;quot; is derived from the acronym of &amp;quot;Acute Minor Thirds&amp;quot;, meaning a minor third sharper than 6/5 but still flatter than a neutral third).&lt;br /&gt;
18-EDO, aka the &amp;quot;third-tone&amp;quot; system, is related to &lt;a class="wiki_link" href="/12edo"&gt;12-tET&lt;/a&gt; by the whole-tone scale (which is &lt;a class="wiki_link" href="/6edo"&gt;6-EDO&lt;/a&gt;), since 18=6*3 and 12=6*2; hence a 12-tET &amp;quot;whole tone&amp;quot; is divided into 3 equal parts in 18-EDO. Since 18=9*2, 18-EDO contains two sets of &lt;a class="wiki_link" href="/9edo"&gt;9-EDO&lt;/a&gt;, offset from each other by a third-tone. 18-EDO is related to &lt;a class="wiki_link" href="/13edo"&gt;13-EDO&lt;/a&gt;, &lt;a class="wiki_link" href="/21edo"&gt;21-EDO&lt;/a&gt;, &lt;a class="wiki_link" href="/23edo"&gt;23-EDO&lt;/a&gt;, and &lt;a class="wiki_link" href="/28edo"&gt;28-EDO&lt;/a&gt; in that all are &lt;a class="wiki_link" href="/Father%20Temperament"&gt;&amp;quot;Father&amp;quot; temperaments&lt;/a&gt; (they temper out 16/15--the difference between a major third and perfect fourth). It is related to &lt;a class="wiki_link" href="/11edo"&gt;11-EDO&lt;/a&gt;, &lt;a class="wiki_link" href="/15edo"&gt;15-EDO&lt;/a&gt;, &lt;a class="wiki_link" href="/25edo"&gt;25-EDO&lt;/a&gt;, and 29-EDO in that they are all &lt;a class="wiki_link" href="/Amity%20Temperament"&gt;&amp;quot;Amity&amp;quot; temperaments&lt;/a&gt; (&amp;quot;Amity&amp;quot; is derived from the acronym of &amp;quot;Acute Minor Thirds&amp;quot;, meaning a minor third sharper than 6/5 but still flatter than a neutral third).&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
&lt;!-- ws:start:WikiTextHeadingRule:8:&amp;lt;h2&amp;gt; --&gt;&lt;h2 id="toc4"&gt;&lt;a name="x18 Equal Divisions of the Octave-Useful Moment-of-Symmetry Scales"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:8 --&gt;Useful Moment-of-Symmetry Scales&lt;/h2&gt;
&lt;!-- ws:start:WikiTextHeadingRule:8:&amp;lt;h2&amp;gt; --&gt;&lt;h2 id="toc4"&gt;&lt;a name="x18 Equal Divisions of the Octave-Useful Moment-of-Symmetry Scales"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:8 --&gt;Useful Moment-of-Symmetry Scales&lt;/h2&gt;