18edo: Difference between revisions
Wikispaces>genewardsmith **Imported revision 232646824 - Original comment: ** |
Wikispaces>genewardsmith **Imported revision 232647018 - 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:genewardsmith|genewardsmith]] and made on <tt>2011-05-28 22: | : This revision was by author [[User:genewardsmith|genewardsmith]] and made on <tt>2011-05-28 22:47:01 UTC</tt>.<br> | ||
: The original revision id was <tt> | : The original revision id was <tt>232647018</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== | ||
The //18 equal division// divides the octave into 18 equal parts of 66.667 cents each. It does not approximate the 3rd harmonic at all, unless a >30¢-error is considered acceptable. In order to access the excellent consonances actually available, one must take a considerably "non-common-practice" approach centering on the chords in the 17-limit [[k*N subgroups|4*18 subgroup]] [[just intonation subgroup]] 2.9.75.21.55.39.51 . On this subgroup it tempers out exactly the same commas as 72 does on the full [[17-limit]], and gives precisely the same tunings. The subgroup can be put into a single chord, for example 32:36:39:42:51:55:64:75 (in terms of 18edo, 0-3-5-7-12-14-18-22), and transpositions and inversions of this chord or its subchords provide plenty of harmonic resources. | The //18 equal division// divides the octave into 18 equal parts of 66.667 cents each. It does not approximate the 3rd harmonic at all, unless a >30¢-error is considered acceptable. In order to access the excellent consonances actually available, one must take a considerably "non-common-practice" approach centering on the chords in the 17-limit [[k*N subgroups|4*18 subgroup]] [[Just intonation subgroups|just intonation subgroup]] 2.9.75.21.55.39.51. On this subgroup it tempers out exactly the same commas as 72 does on the full [[17-limit]], and gives precisely the same tunings. The subgroup can be put into a single chord, for example 32:36:39:42:51:55:64:75 (in terms of 18edo, 0-3-5-7-12-14-18-22), and transpositions and inversions of this chord or its subchords provide plenty of harmonic resources. | ||
===Relationship to Other EDOs=== | ===Relationship to Other EDOs=== | ||
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<!-- ws:start:WikiTextHeadingRule:2:&lt;h2&gt; --><h2 id="toc1"><a name="x18 Equal Divisions of the Octave-Basic Properties"></a><!-- ws:end:WikiTextHeadingRule:2 -->Basic Properties</h2> | <!-- ws:start:WikiTextHeadingRule:2:&lt;h2&gt; --><h2 id="toc1"><a name="x18 Equal Divisions of the Octave-Basic Properties"></a><!-- ws:end:WikiTextHeadingRule:2 -->Basic Properties</h2> | ||
The <em>18 equal division</em> divides the octave into 18 equal parts of 66.667 cents each. It does not approximate the 3rd harmonic at all, unless a &gt;30¢-error is considered acceptable. In order to access the excellent consonances actually available, one must take a considerably &quot;non-common-practice&quot; approach centering on the chords in the 17-limit <a class="wiki_link" href="/k%2AN%20subgroups">4*18 subgroup</a> <a class="wiki_link" href="/ | The <em>18 equal division</em> divides the octave into 18 equal parts of 66.667 cents each. It does not approximate the 3rd harmonic at all, unless a &gt;30¢-error is considered acceptable. In order to access the excellent consonances actually available, one must take a considerably &quot;non-common-practice&quot; approach centering on the chords in the 17-limit <a class="wiki_link" href="/k%2AN%20subgroups">4*18 subgroup</a> <a class="wiki_link" href="/Just%20intonation%20subgroups">just intonation subgroup</a> 2.9.75.21.55.39.51. On this subgroup it tempers out exactly the same commas as 72 does on the full <a class="wiki_link" href="/17-limit">17-limit</a>, and gives precisely the same tunings. The subgroup can be put into a single chord, for example 32:36:39:42:51:55:64:75 (in terms of 18edo, 0-3-5-7-12-14-18-22), and transpositions and inversions of this chord or its subchords provide plenty of harmonic resources.<br /> | ||
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<!-- ws:start:WikiTextHeadingRule:4:&lt;h3&gt; --><h3 id="toc2"><a name="x18 Equal Divisions of the Octave-Basic Properties-Relationship to Other EDOs"></a><!-- ws:end:WikiTextHeadingRule:4 -->Relationship to Other EDOs</h3> | <!-- ws:start:WikiTextHeadingRule:4:&lt;h3&gt; --><h3 id="toc2"><a name="x18 Equal Divisions of the Octave-Basic Properties-Relationship to Other EDOs"></a><!-- ws:end:WikiTextHeadingRule:4 -->Relationship to Other EDOs</h3> | ||