Porcupine: Difference between revisions

Wikispaces>keenanpepper
**Imported revision 246788761 - Original comment: **
Wikispaces>guest
**Imported revision 270416010 - 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:keenanpepper|keenanpepper]] and made on <tt>2011-08-18 16:36:03 UTC</tt>.<br>
: This revision was by author [[User:guest|guest]] and made on <tt>2011-10-31 17:01:16 UTC</tt>.<br>
: The original revision id was <tt>246788761</tt>.<br>
: The original revision id was <tt>270416010</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>
<h4>Original Wikitext content:</h4>
<h4>Original Wikitext content:</h4>
<div style="width:100%; max-height:400pt; overflow:auto; background-color:#f8f9fa; border: 1px solid #eaecf0; padding:0em"><pre style="margin:0px;border:none;background:none;word-wrap:break-word;white-space: pre-wrap ! important" class="old-revision-html">See [[Porcupine family#Porcupine]].</pre></div>
<div style="width:100%; max-height:400pt; overflow:auto; background-color:#f8f9fa; border: 1px solid #eaecf0; padding:0em"><pre style="margin:0px;border:none;background:none;word-wrap:break-word;white-space: pre-wrap ! important" class="old-revision-html">**Porcupine** is a [[Regular Temperaments|linear temperament]] that tempers out 250/243, the porcupine [[Comma|comma]], and whose generator is somewhere around 160-165 cents. It can be thought of as a 5-[[Harmonic Limit|limit]] temperament, a 7-limit one, an 11-limit one, or a 2.3.5.11 [[Subgroup temperaments|subgroup temperament]]. In the 2.3.5.11 subgroup it is one of the best temperaments, with a unique combination of efficiency and accuracy.
 
The basic 5-limit harmonic structure of porcupine can be understood simply by noting that tempering out 250/243 makes (4/3)^2 equivalent to (6/5)^3. In perhaps more familiar musical terms, this means two "perfect fourths" equals three "minor thirds". As a consequence of this, 4/3 is divided into 3 equal parts, and 6/5 is divided into 2 of those same equal parts. This is obviously in stark contrast to [[12edo]], and to meantone in which neither 4/3 nor 6/5 can be divided into any number of equal parts. The "equal tetrachord" formed by dividing 4/3 into 3 equal parts is a characteristic feature of many porcupine scales.</pre></div>
<h4>Original HTML content:</h4>
<h4>Original HTML content:</h4>
<div style="width:100%; max-height:400pt; overflow:auto; background-color:#f8f9fa; border: 1px solid #eaecf0; padding:0em"><pre style="margin:0px;border:none;background:none;word-wrap:break-word;width:200%;white-space: pre-wrap ! important" class="old-revision-html">&lt;html&gt;&lt;head&gt;&lt;title&gt;Porcupine&lt;/title&gt;&lt;/head&gt;&lt;body&gt;See &lt;a class="wiki_link" href="/Porcupine%20family#Porcupine"&gt;Porcupine family&lt;/a&gt;.&lt;/body&gt;&lt;/html&gt;</pre></div>
<div style="width:100%; max-height:400pt; overflow:auto; background-color:#f8f9fa; border: 1px solid #eaecf0; padding:0em"><pre style="margin:0px;border:none;background:none;word-wrap:break-word;width:200%;white-space: pre-wrap ! important" class="old-revision-html">&lt;html&gt;&lt;head&gt;&lt;title&gt;Porcupine&lt;/title&gt;&lt;/head&gt;&lt;body&gt;&lt;strong&gt;Porcupine&lt;/strong&gt; is a &lt;a class="wiki_link" href="/Regular%20Temperaments"&gt;linear temperament&lt;/a&gt; that tempers out 250/243, the porcupine &lt;a class="wiki_link" href="/Comma"&gt;comma&lt;/a&gt;, and whose generator is somewhere around 160-165 cents. It can be thought of as a 5-&lt;a class="wiki_link" href="/Harmonic%20Limit"&gt;limit&lt;/a&gt; temperament, a 7-limit one, an 11-limit one, or a 2.3.5.11 &lt;a class="wiki_link" href="/Subgroup%20temperaments"&gt;subgroup temperament&lt;/a&gt;. In the 2.3.5.11 subgroup it is one of the best temperaments, with a unique combination of efficiency and accuracy.&lt;br /&gt;
&lt;br /&gt;
The basic 5-limit harmonic structure of porcupine can be understood simply by noting that tempering out 250/243 makes (4/3)^2 equivalent to (6/5)^3. In perhaps more familiar musical terms, this means two &amp;quot;perfect fourths&amp;quot; equals three &amp;quot;minor thirds&amp;quot;. As a consequence of this, 4/3 is divided into 3 equal parts, and 6/5 is divided into 2 of those same equal parts. This is obviously in stark contrast to &lt;a class="wiki_link" href="/12edo"&gt;12edo&lt;/a&gt;, and to meantone in which neither 4/3 nor 6/5 can be divided into any number of equal parts. The &amp;quot;equal tetrachord&amp;quot; formed by dividing 4/3 into 3 equal parts is a characteristic feature of many porcupine scales.&lt;/body&gt;&lt;/html&gt;</pre></div>