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Wikispaces>genewardsmith **Imported revision 320352610 - Original comment: ** |
Wikispaces>Cenobyte **Imported revision 370839812 - 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: | : This revision was by author [[User:Cenobyte|Cenobyte]] and made on <tt>2012-10-07 04:10:49 UTC</tt>.<br> | ||
: The original revision id was <tt> | : The original revision id was <tt>370839812</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">[[toc|flat]] | <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">[[toc|flat]] | ||
**7 Equal Divisions of the Octave** | **7 Equal Divisions of the Octave** | ||
="neutral diatonic"= | ="neutral diatonic"= | ||
7-edo divides the 1200-cent [[octave]] into 7 equal parts, making its smallest interval [[cent|171.428¢]], or the seventh root of 2. It is the fourth [[prime numbers|prime]] edo, after [[2edo]], [[3edo]] and [[5edo]]. | 7-edo divides the 1200-cent [[octave]] into 7 equal parts, making its smallest interval [[cent|171.428¢]], or the seventh root of 2. It is the fourth [[prime numbers|prime]] edo, after [[2edo]], [[3edo]] and [[5edo]]. | ||
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A Thai xylophone measured by Morton (1974) "varied only plus or minus 5 cents," from 7-TET. A Ugandan Chopi xylophone measured by Haddon (1952) was also tuned to this system. | A Thai xylophone measured by Morton (1974) "varied only plus or minus 5 cents," from 7-TET. A Ugandan Chopi xylophone measured by Haddon (1952) was also tuned to this system. | ||
=Intervals in 7-edo= | =Intervals in 7-edo= | ||
|| **Interval** || **Interval** | || **Interval** || **Interval** | ||
**size** | **size** | ||
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|| 7 (0) || 1200.0 || eighth || exactly 2/1 || | || 7 (0) || 1200.0 || eighth || exactly 2/1 || | ||
=Related scales= | =Related scales= | ||
* Related in a lateral way to traditional Thai music. | * Related in a lateral way to traditional Thai music. | ||
==Notation== | ==Notation== | ||
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=== === | === === | ||
=Music= | =Music= | ||
[[http://sethares.engr.wisc.edu/mp3s/PagansRevenge.mp3|Pagan's Revenge]] by Bill Sethares (synthetic gamelan) | [[http://sethares.engr.wisc.edu/mp3s/PagansRevenge.mp3|Pagan's Revenge]] by Bill Sethares (synthetic gamelan) | ||
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[[http://www.seraph.it/dep/det/7edo%20dance.mp3|7edo Dance]] by Carlo Serafini | [[http://www.seraph.it/dep/det/7edo%20dance.mp3|7edo Dance]] by Carlo Serafini | ||
[[http://micro.soonlabel.com/gene_ward_smith/Others/Winchester/06%20-%206.%207%20octave.mp3|Comets Over Flatland 6]] by [[Randy Winchester]] | [[http://micro.soonlabel.com/gene_ward_smith/Others/Winchester/06%20-%206.%207%20octave.mp3|Comets Over Flatland 6]] by [[Randy Winchester]] | ||
[[http:// | [[http://media.soundcloud.com/stream/IUcgFYhtu3Rk?stream_token=4QIvd|Sävelmä]] by [[http://soundcloud.com/juhani-nuorvala/s-velm-long-version|Juhani Nuorvala]] | ||
=Commas= | =Commas= | ||
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<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"><html><head><title>7edo</title></head><body><!-- ws:start:WikiTextTocRule:20:&lt;img id=&quot;wikitext@@toc@@flat&quot; class=&quot;WikiMedia WikiMediaTocFlat&quot; title=&quot;Table of Contents&quot; src=&quot;/site/embedthumbnail/toc/flat?w=100&amp;h=16&quot;/&gt; --><!-- ws:end:WikiTextTocRule:20 --><!-- ws:start:WikiTextTocRule:21: --><a href="#x&quot;neutral diatonic&quot;">&quot;neutral diatonic&quot;</a><!-- ws:end:WikiTextTocRule:21 --><!-- ws:start:WikiTextTocRule:22: --> | <a href="#Intervals in 7-edo">Intervals in 7-edo</a><!-- ws:end:WikiTextTocRule:22 --><!-- ws:start:WikiTextTocRule:23: --> | <a href="#Related scales">Related scales</a><!-- ws:end:WikiTextTocRule:23 --><!-- ws:start:WikiTextTocRule:24: --><!-- ws:end:WikiTextTocRule:24 --><!-- ws:start:WikiTextTocRule:25: --><!-- ws:end:WikiTextTocRule:25 --><!-- ws:start:WikiTextTocRule:26: --><!-- ws:end:WikiTextTocRule:26 --><!-- ws:start:WikiTextTocRule:27: --><!-- ws:end:WikiTextTocRule:27 --><!-- ws:start:WikiTextTocRule:28: --><!-- ws:end:WikiTextTocRule:28 --><!-- ws:start:WikiTextTocRule:29: --> | <a href="#Music">Music</a><!-- ws:end:WikiTextTocRule:29 --><!-- ws:start:WikiTextTocRule:30: --> | <a href="#Commas">Commas</a><!-- ws:end:WikiTextTocRule:30 --><!-- ws:start:WikiTextTocRule:31: --> | <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"><html><head><title>7edo</title></head><body><!-- ws:start:WikiTextTocRule:20:&lt;img id=&quot;wikitext@@toc@@flat&quot; class=&quot;WikiMedia WikiMediaTocFlat&quot; title=&quot;Table of Contents&quot; src=&quot;/site/embedthumbnail/toc/flat?w=100&amp;h=16&quot;/&gt; --><!-- ws:end:WikiTextTocRule:20 --><!-- ws:start:WikiTextTocRule:21: --><a href="#x&quot;neutral diatonic&quot;">&quot;neutral diatonic&quot;</a><!-- ws:end:WikiTextTocRule:21 --><!-- ws:start:WikiTextTocRule:22: --> | <a href="#Intervals in 7-edo">Intervals in 7-edo</a><!-- ws:end:WikiTextTocRule:22 --><!-- ws:start:WikiTextTocRule:23: --> | <a href="#Related scales">Related scales</a><!-- ws:end:WikiTextTocRule:23 --><!-- ws:start:WikiTextTocRule:24: --><!-- ws:end:WikiTextTocRule:24 --><!-- ws:start:WikiTextTocRule:25: --><!-- ws:end:WikiTextTocRule:25 --><!-- ws:start:WikiTextTocRule:26: --><!-- ws:end:WikiTextTocRule:26 --><!-- ws:start:WikiTextTocRule:27: --><!-- ws:end:WikiTextTocRule:27 --><!-- ws:start:WikiTextTocRule:28: --><!-- ws:end:WikiTextTocRule:28 --><!-- ws:start:WikiTextTocRule:29: --> | <a href="#Music">Music</a><!-- ws:end:WikiTextTocRule:29 --><!-- ws:start:WikiTextTocRule:30: --> | <a href="#Commas">Commas</a><!-- ws:end:WikiTextTocRule:30 --><!-- ws:start:WikiTextTocRule:31: --> | ||
<!-- ws:end:WikiTextTocRule:31 --><br /> | <!-- ws:end:WikiTextTocRule:31 --><br /> | ||
<strong>7 Equal Divisions of the Octave</strong><br /> | <strong>7 Equal Divisions of the Octave</strong><br /> | ||
<br /> | <br /> | ||
<!-- ws:start:WikiTextHeadingRule:0:&lt;h1&gt; --><h1 id="toc0"><a name="x&quot;neutral diatonic&quot;"></a><!-- ws:end:WikiTextHeadingRule:0 -->&quot;neutral diatonic&quot;</h1> | <!-- ws:start:WikiTextHeadingRule:0:&lt;h1&gt; --><h1 id="toc0"><a name="x&quot;neutral diatonic&quot;"></a><!-- ws:end:WikiTextHeadingRule:0 -->&quot;neutral diatonic&quot;</h1> | ||
<br /> | <br /> | ||
7-edo divides the 1200-cent <a class="wiki_link" href="/octave">octave</a> into 7 equal parts, making its smallest interval <a class="wiki_link" href="/cent">171.428¢</a>, or the seventh root of 2. It is the fourth <a class="wiki_link" href="/prime%20numbers">prime</a> edo, after <a class="wiki_link" href="/2edo">2edo</a>, <a class="wiki_link" href="/3edo">3edo</a> and <a class="wiki_link" href="/5edo">5edo</a>.<br /> | 7-edo divides the 1200-cent <a class="wiki_link" href="/octave">octave</a> into 7 equal parts, making its smallest interval <a class="wiki_link" href="/cent">171.428¢</a>, or the seventh root of 2. It is the fourth <a class="wiki_link" href="/prime%20numbers">prime</a> edo, after <a class="wiki_link" href="/2edo">2edo</a>, <a class="wiki_link" href="/3edo">3edo</a> and <a class="wiki_link" href="/5edo">5edo</a>.<br /> | ||
<br /> | <br /> | ||
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<br /> | <br /> | ||
Similarly, in equi-heptatonic systems the desire for harmonic sound may dictate constant adjustments of intonation away from the theoretical interval of 171 cents. One of the most impressive areas in Africa in which a pen-equidistant heptatonic scale is combined with a distinctively harmonic style based on singing in intervals of thirds plus fifths, or thirds plus fourths, is the eastern Angolan culture area. This music is heptatonic and non-modal; i.e., there is no concept of major or minor thirds as distinctive intervals. In principle all the thirds are neutral, but in practice the thirds rendered by the singers often approximate natural major thirds (386 cents), especially at points of rest. In this manner, the principles of equidistance and harmonic euphony are accommodated within one tonal-harmonic system. For the notation of such music, a seven-line stave is most appropriate, with each horizontal line representing one pitch level.<br /> | Similarly, in equi-heptatonic systems the desire for harmonic sound may dictate constant adjustments of intonation away from the theoretical interval of 171 cents. One of the most impressive areas in Africa in which a pen-equidistant heptatonic scale is combined with a distinctively harmonic style based on singing in intervals of thirds plus fifths, or thirds plus fourths, is the eastern Angolan culture area. This music is heptatonic and non-modal; i.e., there is no concept of major or minor thirds as distinctive intervals. In principle all the thirds are neutral, but in practice the thirds rendered by the singers often approximate natural major thirds (386 cents), especially at points of rest. In this manner, the principles of equidistance and harmonic euphony are accommodated within one tonal-harmonic system. For the notation of such music, a seven-line stave is most appropriate, with each horizontal line representing one pitch level.<br /> | ||
<u><em>(&quot;African music.&quot; Encyclopædia Britannica. 2009. Encyclopædia Britannica Online. 05 Jul. 2009 &lt;<!-- ws:start:WikiTextUrlRule: | <u><em>(&quot;African music.&quot; Encyclopædia Britannica. 2009. Encyclopædia Britannica Online. 05 Jul. 2009 &lt;<!-- ws:start:WikiTextUrlRule:679:http://www.britannica.com/EBchecked/topic/719112/African-music --><a class="wiki_link_ext" href="http://www.britannica.com/EBchecked/topic/719112/African-music" rel="nofollow">http://www.britannica.com/EBchecked/topic/719112/African-music</a><!-- ws:end:WikiTextUrlRule:679 -->&gt;.</em></u>)<br /> | ||
<br /> | <br /> | ||
A Thai xylophone measured by Morton (1974) &quot;varied only plus or minus 5 cents,&quot; from 7-TET. A Ugandan Chopi xylophone measured by Haddon (1952) was also tuned to this system.<br /> | A Thai xylophone measured by Morton (1974) &quot;varied only plus or minus 5 cents,&quot; from 7-TET. A Ugandan Chopi xylophone measured by Haddon (1952) was also tuned to this system.<br /> | ||
<br /> | <br /> | ||
<!-- ws:start:WikiTextHeadingRule:2:&lt;h1&gt; --><h1 id="toc1"><a name="Intervals in 7-edo"></a><!-- ws:end:WikiTextHeadingRule:2 -->Intervals in 7-edo</h1> | <!-- ws:start:WikiTextHeadingRule:2:&lt;h1&gt; --><h1 id="toc1"><a name="Intervals in 7-edo"></a><!-- ws:end:WikiTextHeadingRule:2 -->Intervals in 7-edo</h1> | ||
<table class="wiki_table"> | <table class="wiki_table"> | ||
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<br /> | <br /> | ||
<!-- ws:start:WikiTextHeadingRule:4:&lt;h1&gt; --><h1 id="toc2"><a name="Related scales"></a><!-- ws:end:WikiTextHeadingRule:4 -->Related scales</h1> | <!-- ws:start:WikiTextHeadingRule:4:&lt;h1&gt; --><h1 id="toc2"><a name="Related scales"></a><!-- ws:end:WikiTextHeadingRule:4 -->Related scales</h1> | ||
<ul><li>Related in a lateral way to traditional Thai music.</li></ul><!-- ws:start:WikiTextHeadingRule:6:&lt;h2&gt; --><h2 id="toc3"><a name="Related scales-Notation"></a><!-- ws:end:WikiTextHeadingRule:6 -->Notation</h2> | <ul><li>Related in a lateral way to traditional Thai music.</li></ul><!-- ws:start:WikiTextHeadingRule:6:&lt;h2&gt; --><h2 id="toc3"><a name="Related scales-Notation"></a><!-- ws:end:WikiTextHeadingRule:6 -->Notation</h2> | ||
<ul><li>Notatable on a five-line staff without accidentals.</li></ul><!-- ws:start:WikiTextHeadingRule:8:&lt;h2&gt; --><h2 id="toc4"><a name="Related scales-Harmony"></a><!-- ws:end:WikiTextHeadingRule:8 -->Harmony</h2> | <ul><li>Notatable on a five-line staff without accidentals.</li></ul><!-- ws:start:WikiTextHeadingRule:8:&lt;h2&gt; --><h2 id="toc4"><a name="Related scales-Harmony"></a><!-- ws:end:WikiTextHeadingRule:8 -->Harmony</h2> | ||
There is no distinction between Major or Minor; each pitch class is unique.<br /> | There is no distinction between Major or Minor; each pitch class is unique.<br /> | ||
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<!-- ws:start:WikiTextHeadingRule:14:&lt;h3&gt; --><h3 id="toc7"><!-- ws:end:WikiTextHeadingRule:14 --> </h3> | <!-- ws:start:WikiTextHeadingRule:14:&lt;h3&gt; --><h3 id="toc7"><!-- ws:end:WikiTextHeadingRule:14 --> </h3> | ||
<!-- ws:start:WikiTextHeadingRule:16:&lt;h1&gt; --><h1 id="toc8"><a name="Music"></a><!-- ws:end:WikiTextHeadingRule:16 -->Music</h1> | <!-- ws:start:WikiTextHeadingRule:16:&lt;h1&gt; --><h1 id="toc8"><a name="Music"></a><!-- ws:end:WikiTextHeadingRule:16 -->Music</h1> | ||
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<a class="wiki_link_ext" href="http://sethares.engr.wisc.edu/mp3s/PagansRevenge.mp3" rel="nofollow">Pagan's Revenge</a> by Bill Sethares (synthetic gamelan)<br /> | <a class="wiki_link_ext" href="http://sethares.engr.wisc.edu/mp3s/PagansRevenge.mp3" rel="nofollow">Pagan's Revenge</a> by Bill Sethares (synthetic gamelan)<br /> | ||
<a class="wiki_link_ext" href="http://www.akjmusic.com/audio/i_dream_of_tibet.mp3" rel="nofollow">I dream of Tibet</a> by <a class="wiki_link_ext" href="http://www.akjmusic.com/works.html" rel="nofollow">Aaron K. Johnson</a> (electronic swirlies)<br /> | <a class="wiki_link_ext" href="http://www.akjmusic.com/audio/i_dream_of_tibet.mp3" rel="nofollow">I dream of Tibet</a> by <a class="wiki_link_ext" href="http://www.akjmusic.com/works.html" rel="nofollow">Aaron K. Johnson</a> (electronic swirlies)<br /> | ||
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<a class="wiki_link_ext" href="http://www.seraph.it/dep/det/7edo%20dance.mp3" rel="nofollow">7edo Dance</a> by Carlo Serafini<br /> | <a class="wiki_link_ext" href="http://www.seraph.it/dep/det/7edo%20dance.mp3" rel="nofollow">7edo Dance</a> by Carlo Serafini<br /> | ||
<a class="wiki_link_ext" href="http://micro.soonlabel.com/gene_ward_smith/Others/Winchester/06%20-%206.%207%20octave.mp3" rel="nofollow">Comets Over Flatland 6</a> by <a class="wiki_link" href="/Randy%20Winchester">Randy Winchester</a><br /> | <a class="wiki_link_ext" href="http://micro.soonlabel.com/gene_ward_smith/Others/Winchester/06%20-%206.%207%20octave.mp3" rel="nofollow">Comets Over Flatland 6</a> by <a class="wiki_link" href="/Randy%20Winchester">Randy Winchester</a><br /> | ||
<a class="wiki_link_ext" href="http:// | <a class="wiki_link_ext" href="http://media.soundcloud.com/stream/IUcgFYhtu3Rk?stream_token=4QIvd" rel="nofollow">Sävelmä</a> by <a class="wiki_link_ext" href="http://soundcloud.com/juhani-nuorvala/s-velm-long-version" rel="nofollow">Juhani Nuorvala</a><br /> | ||
<br /> | <br /> | ||
<!-- ws:start:WikiTextHeadingRule:18:&lt;h1&gt; --><h1 id="toc9"><a name="Commas"></a><!-- ws:end:WikiTextHeadingRule:18 -->Commas</h1> | <!-- ws:start:WikiTextHeadingRule:18:&lt;h1&gt; --><h1 id="toc9"><a name="Commas"></a><!-- ws:end:WikiTextHeadingRule:18 -->Commas</h1> |
Revision as of 04:10, 7 October 2012
IMPORTED REVISION FROM WIKISPACES
This is an imported revision from Wikispaces. The revision metadata is included below for reference:
- This revision was by author Cenobyte and made on 2012-10-07 04:10:49 UTC.
- The original revision id was 370839812.
- The revision comment was:
The revision contents are below, presented both in the original Wikispaces Wikitext format, and in HTML exactly as Wikispaces rendered it.
Original Wikitext content:
[[toc|flat]] **7 Equal Divisions of the Octave** ="neutral diatonic"= 7-edo divides the 1200-cent [[octave]] into 7 equal parts, making its smallest interval [[cent|171.428¢]], or the seventh root of 2. It is the fourth [[prime numbers|prime]] edo, after [[2edo]], [[3edo]] and [[5edo]]. Equi-heptatonic scales are used in non-western music in African cultures and it has been speculated in "Indian music:history and structure", that the Indian three-sruti interval of 165 cents is close enough to be mistaken for 171 cents. (or 1.71 semitones). 7-tet can be thought of as result of stacking seven 11/9s on top of each other, and then tempering to remove the comma 2^(-2) 3^(-14) 11^7. The seventh of 7-edo is almost exactly the 29th harmonic ([[29_16|29/16]]), which can have a very agreeable sound with harmonic timbres. However it also finds itself nested between ratios such as 20/11 and 9/5, which gives it considerably higher [[harmonic entropy]] than [[harmonic seventh|7/4]], a much simpler overtone seventh. Similarly, in equi-heptatonic systems the desire for harmonic sound may dictate constant adjustments of intonation away from the theoretical interval of 171 cents. One of the most impressive areas in Africa in which a pen-equidistant heptatonic scale is combined with a distinctively harmonic style based on singing in intervals of thirds plus fifths, or thirds plus fourths, is the eastern Angolan culture area. This music is heptatonic and non-modal; i.e., there is no concept of major or minor thirds as distinctive intervals. In principle all the thirds are neutral, but in practice the thirds rendered by the singers often approximate natural major thirds (386 cents), especially at points of rest. In this manner, the principles of equidistance and harmonic euphony are accommodated within one tonal-harmonic system. For the notation of such music, a seven-line stave is most appropriate, with each horizontal line representing one pitch level. __//("African music." Encyclopædia Britannica. 2009. Encyclopædia Britannica Online. 05 Jul. 2009 <http://www.britannica.com/EBchecked/topic/719112/African-music>.//__) A Thai xylophone measured by Morton (1974) "varied only plus or minus 5 cents," from 7-TET. A Ugandan Chopi xylophone measured by Haddon (1952) was also tuned to this system. =Intervals in 7-edo= || **Interval** || **Interval** **size** **in ¢** || **Closest** **diatonic** **interval name** || **The "neighborhood" of just intervals** || || 0 || 0.0 || unison / prime || exactly 1/1 || || 1 || 171,429 || second || 6,424 c from Ptolemy (neutral) second 11/10 3,215 c from second 54/49 -10,976 c from (Didymus) major second (small whole tone) 10/9 || || 2 || 342,857 || third || -4,551 c from neutral third 11/9 || || 3 || 514,286 || fourth || 16,241 c from just fourth 4/3 (498,045 c) -5,265 c from wide fourth 27/20 || || 4 || 685,714 || fifth || 5,265 c from narrow fifth 40/27 -16,241 c from just fifth 3/2 (701,955 c) || || 5 || 857,143 || sixth || 4,551 c from neutral sixth 18/11 || || 6 || 1028,571 || seventh || 10,975 c from (Didymus) minor seventh 9/5 -6,425 c from neutral seventh 20/11 1,006 c from the 29th harmonic 29/16 -3,216 c from seventh 49/27 || || 7 (0) || 1200.0 || eighth || exactly 2/1 || =Related scales= * Related in a lateral way to traditional Thai music. ==Notation== * Notatable on a five-line staff without accidentals. ==Harmony== There is no distinction between Major or Minor; each pitch class is unique. ==Melody== There is a neutral feel between whole tone scale and major/minor diatonic scale. The second 171,429 c works well as a basic step for melodic progression. The step from seventh to octave is too large for the leading tone. ==Relative tuning accuracy== 7-edo is the third [[The Riemann Zeta Function and Tuning#Zeta%20EDO%20lists|zeta integral edo]]. === === =Music= [[http://sethares.engr.wisc.edu/mp3s/PagansRevenge.mp3|Pagan's Revenge]] by Bill Sethares (synthetic gamelan) [[http://www.akjmusic.com/audio/i_dream_of_tibet.mp3|I dream of Tibet]] by [[http://www.akjmusic.com/works.html|Aaron K. Johnson]] (electronic swirlies) [[http://micro.soonlabel.com/gene_ward_smith/Others/Walker/Seven%20Equal%20Trio.mp3|Seven Equal Trio]] by [[http://robertinventor.tripod.com/tunes/tunes.htm#7_equal_trio|Robert Walker]] ((synth) violin, viola, glockenspiel) [[http://micro.soonlabel.com/gene_ward_smith/Others/Hunt/7ET.mp3|Two-part Invention in 7TET]] by [[http://www.h-pi.com/musicFiles.html|Aaron Hunt]] [[http://www.uvnitr.cz/flaoyg/flao_yg/pavouci.html|Pavouci]], [[http://www.uvnitr.cz/flaoyg/flao_yg/kelt.html|Kelt]] by Milan Guštar [[http://www.seraph.it/dep/det/7edo%20dance.mp3|7edo Dance]] by Carlo Serafini [[http://micro.soonlabel.com/gene_ward_smith/Others/Winchester/06%20-%206.%207%20octave.mp3|Comets Over Flatland 6]] by [[Randy Winchester]] [[http://media.soundcloud.com/stream/IUcgFYhtu3Rk?stream_token=4QIvd|Sävelmä]] by [[http://soundcloud.com/juhani-nuorvala/s-velm-long-version|Juhani Nuorvala]] =Commas= 7 EDO tempers out the following commas. (Note: This assumes val < 7 11 16 20 24 26 |.) ||~ Comma ||~ Monzo ||~ Cents ||~ Name 1 ||~ Name 2 ||~ Name 3 || ||= 2187/2048 || | -11 7 > ||> 113.69 ||= Apotome ||= ||= || ||= 135/128 || | -7 3 1 > ||> 92.18 ||= Major Chroma ||= Major Limma ||= Pelogic Comma || ||= 250/243 || | 1 -5 3 > ||> 49.17 ||= Maximal Diesis ||= Porcupine Comma ||= || ||= 20000/19683 || | 5 -9 4 > ||> 27.66 ||= Minimal Diesis ||= Tetracot Comma ||= || ||= 81/80 || | -4 4 -1 > ||> 21.51 ||= Syntonic Comma ||= Didymos Comma ||= Meantone Comma || ||= 1600000/1594323 || | 9 -13 5 > ||> 6.15 ||= Amity Comma ||= ||= || ||= 36/35 || | 2 2 -1 -1 > ||> 48.77 ||= Septimal Quarter Tone ||= ||= || ||= 525/512 || | -9 1 2 1 > ||> 43.41 ||= Avicennma ||= Avicenna's Enharmonic Diesis ||= || ||= 64/63 || | 6 -2 0 -1 > ||> 27.26 ||= Septimal Comma ||= Archytas' Comma ||= Leipziger Komma || ||= 875/864 || | -5 -3 3 1 > ||> 21.90 ||= Keema ||= ||= || ||= 5120/5103 || | 10 -6 1 -1 > ||> 5.76 ||= Hemifamity ||= ||= || ||= 6144/6125 || | 11 1 -3 -2 > ||> 5.36 ||= Porwell ||= ||= || ||= 4375/4374 || | -1 -7 4 1 > ||> 0.40 ||= Ragisma ||= ||= || ||= 394839/394762 || | 47 -7 -7 -7 > ||> 0.34 ||= Akjaysma ||= 5\7 Octave Comma ||= || ||= 100/99 || | 2 -2 2 0 -1 > ||> 17.40 ||= Ptolemisma ||= ||= || ||= 121/120 || | -3 -1 -1 0 2 > ||> 14.37 ||= Biyatisma ||= ||= || ||= 176/175 || | 4 0 -2 -1 1 > ||> 9.86 ||= Valinorsma ||= ||= || ||= 65536/65219 || | 16 0 0 -2 -3 > ||> 8.39 ||= Orgonisma ||= ||= || ||= 243/242 || | -1 5 0 0 -2 > ||> 7.14 ||= Rastma ||= ||= || ||= 385/384 || | -7 -1 1 1 1 > ||> 4.50 ||= Keenanisma ||= ||= || ||= 4000/3993 || | 5 -1 3 0 -3 > ||> 3.03 ||= Wizardharry ||= ||= ||
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<html><head><title>7edo</title></head><body><!-- ws:start:WikiTextTocRule:20:<img id="wikitext@@toc@@flat" class="WikiMedia WikiMediaTocFlat" title="Table of Contents" src="/site/embedthumbnail/toc/flat?w=100&h=16"/> --><!-- ws:end:WikiTextTocRule:20 --><!-- ws:start:WikiTextTocRule:21: --><a href="#x"neutral diatonic"">"neutral diatonic"</a><!-- ws:end:WikiTextTocRule:21 --><!-- ws:start:WikiTextTocRule:22: --> | <a href="#Intervals in 7-edo">Intervals in 7-edo</a><!-- ws:end:WikiTextTocRule:22 --><!-- ws:start:WikiTextTocRule:23: --> | <a href="#Related scales">Related scales</a><!-- ws:end:WikiTextTocRule:23 --><!-- ws:start:WikiTextTocRule:24: --><!-- ws:end:WikiTextTocRule:24 --><!-- ws:start:WikiTextTocRule:25: --><!-- ws:end:WikiTextTocRule:25 --><!-- ws:start:WikiTextTocRule:26: --><!-- ws:end:WikiTextTocRule:26 --><!-- ws:start:WikiTextTocRule:27: --><!-- ws:end:WikiTextTocRule:27 --><!-- ws:start:WikiTextTocRule:28: --><!-- ws:end:WikiTextTocRule:28 --><!-- ws:start:WikiTextTocRule:29: --> | <a href="#Music">Music</a><!-- ws:end:WikiTextTocRule:29 --><!-- ws:start:WikiTextTocRule:30: --> | <a href="#Commas">Commas</a><!-- ws:end:WikiTextTocRule:30 --><!-- ws:start:WikiTextTocRule:31: --> <!-- ws:end:WikiTextTocRule:31 --><br /> <strong>7 Equal Divisions of the Octave</strong><br /> <br /> <!-- ws:start:WikiTextHeadingRule:0:<h1> --><h1 id="toc0"><a name="x"neutral diatonic""></a><!-- ws:end:WikiTextHeadingRule:0 -->"neutral diatonic"</h1> <br /> 7-edo divides the 1200-cent <a class="wiki_link" href="/octave">octave</a> into 7 equal parts, making its smallest interval <a class="wiki_link" href="/cent">171.428¢</a>, or the seventh root of 2. It is the fourth <a class="wiki_link" href="/prime%20numbers">prime</a> edo, after <a class="wiki_link" href="/2edo">2edo</a>, <a class="wiki_link" href="/3edo">3edo</a> and <a class="wiki_link" href="/5edo">5edo</a>.<br /> <br /> Equi-heptatonic scales are used in non-western music in African cultures and it has been speculated in "Indian music:history and structure", that the Indian three-sruti interval of 165 cents is close enough to be mistaken for 171 cents. (or 1.71 semitones).<br /> 7-tet can be thought of as result of stacking seven 11/9s on top of each other, and then tempering to remove the comma 2^(-2) 3^(-14) 11^7.<br /> <br /> The seventh of 7-edo is almost exactly the 29th harmonic (<a class="wiki_link" href="/29_16">29/16</a>), which can have a very agreeable sound with harmonic timbres. However it also finds itself nested between ratios such as 20/11 and 9/5, which gives it considerably higher <a class="wiki_link" href="/harmonic%20entropy">harmonic entropy</a> than <a class="wiki_link" href="/harmonic%20seventh">7/4</a>, a much simpler overtone seventh.<br /> <br /> Similarly, in equi-heptatonic systems the desire for harmonic sound may dictate constant adjustments of intonation away from the theoretical interval of 171 cents. One of the most impressive areas in Africa in which a pen-equidistant heptatonic scale is combined with a distinctively harmonic style based on singing in intervals of thirds plus fifths, or thirds plus fourths, is the eastern Angolan culture area. This music is heptatonic and non-modal; i.e., there is no concept of major or minor thirds as distinctive intervals. In principle all the thirds are neutral, but in practice the thirds rendered by the singers often approximate natural major thirds (386 cents), especially at points of rest. In this manner, the principles of equidistance and harmonic euphony are accommodated within one tonal-harmonic system. For the notation of such music, a seven-line stave is most appropriate, with each horizontal line representing one pitch level.<br /> <u><em>("African music." Encyclopædia Britannica. 2009. Encyclopædia Britannica Online. 05 Jul. 2009 <<!-- ws:start:WikiTextUrlRule:679:http://www.britannica.com/EBchecked/topic/719112/African-music --><a class="wiki_link_ext" href="http://www.britannica.com/EBchecked/topic/719112/African-music" rel="nofollow">http://www.britannica.com/EBchecked/topic/719112/African-music</a><!-- ws:end:WikiTextUrlRule:679 -->>.</em></u>)<br /> <br /> A Thai xylophone measured by Morton (1974) "varied only plus or minus 5 cents," from 7-TET. A Ugandan Chopi xylophone measured by Haddon (1952) was also tuned to this system.<br /> <br /> <!-- ws:start:WikiTextHeadingRule:2:<h1> --><h1 id="toc1"><a name="Intervals in 7-edo"></a><!-- ws:end:WikiTextHeadingRule:2 -->Intervals in 7-edo</h1> <table class="wiki_table"> <tr> <td><strong>Interval</strong><br /> </td> <td><strong>Interval</strong><br /> <strong>size</strong><br /> <strong>in ¢</strong><br /> </td> <td><strong>Closest</strong><br /> <strong>diatonic</strong><br /> <strong>interval name</strong><br /> </td> <td><strong>The "neighborhood" of just intervals</strong><br /> </td> </tr> <tr> <td>0<br /> </td> <td>0.0<br /> </td> <td>unison / prime<br /> </td> <td>exactly 1/1<br /> </td> </tr> <tr> <td>1<br /> </td> <td>171,429<br /> </td> <td>second<br /> </td> <td>6,424 c from Ptolemy (neutral) second 11/10<br /> 3,215 c from second 54/49<br /> -10,976 c from (Didymus) major second (small whole tone) 10/9<br /> </td> </tr> <tr> <td>2<br /> </td> <td>342,857<br /> </td> <td>third<br /> </td> <td>-4,551 c from neutral third 11/9<br /> </td> </tr> <tr> <td>3<br /> </td> <td>514,286<br /> </td> <td>fourth<br /> </td> <td>16,241 c from just fourth 4/3 (498,045 c)<br /> -5,265 c from wide fourth 27/20<br /> </td> </tr> <tr> <td>4<br /> </td> <td>685,714<br /> </td> <td>fifth<br /> </td> <td>5,265 c from narrow fifth 40/27<br /> -16,241 c from just fifth 3/2 (701,955 c)<br /> </td> </tr> <tr> <td>5<br /> </td> <td>857,143<br /> </td> <td>sixth<br /> </td> <td>4,551 c from neutral sixth 18/11<br /> </td> </tr> <tr> <td>6<br /> </td> <td>1028,571<br /> </td> <td>seventh<br /> </td> <td>10,975 c from (Didymus) minor seventh 9/5<br /> -6,425 c from neutral seventh 20/11<br /> 1,006 c from the 29th harmonic 29/16<br /> -3,216 c from seventh 49/27<br /> </td> </tr> <tr> <td>7 (0)<br /> </td> <td>1200.0<br /> </td> <td>eighth<br /> </td> <td>exactly 2/1<br /> </td> </tr> </table> <br /> <!-- ws:start:WikiTextHeadingRule:4:<h1> --><h1 id="toc2"><a name="Related scales"></a><!-- ws:end:WikiTextHeadingRule:4 -->Related scales</h1> <ul><li>Related in a lateral way to traditional Thai music.</li></ul><!-- ws:start:WikiTextHeadingRule:6:<h2> --><h2 id="toc3"><a name="Related scales-Notation"></a><!-- ws:end:WikiTextHeadingRule:6 -->Notation</h2> <ul><li>Notatable on a five-line staff without accidentals.</li></ul><!-- ws:start:WikiTextHeadingRule:8:<h2> --><h2 id="toc4"><a name="Related scales-Harmony"></a><!-- ws:end:WikiTextHeadingRule:8 -->Harmony</h2> There is no distinction between Major or Minor; each pitch class is unique.<br /> <!-- ws:start:WikiTextHeadingRule:10:<h2> --><h2 id="toc5"><a name="Related scales-Melody"></a><!-- ws:end:WikiTextHeadingRule:10 -->Melody</h2> There is a neutral feel between whole tone scale and major/minor diatonic scale. The second 171,429 c works well as a basic step for melodic progression.<br /> The step from seventh to octave is too large for the leading tone.<br /> <!-- ws:start:WikiTextHeadingRule:12:<h2> --><h2 id="toc6"><a name="Related scales-Relative tuning accuracy"></a><!-- ws:end:WikiTextHeadingRule:12 -->Relative tuning accuracy</h2> 7-edo is the third <a class="wiki_link" href="/The%20Riemann%20Zeta%20Function%20and%20Tuning#Zeta%20EDO%20lists">zeta integral edo</a>.<br /> <br /> <!-- ws:start:WikiTextHeadingRule:14:<h3> --><h3 id="toc7"><!-- ws:end:WikiTextHeadingRule:14 --> </h3> <!-- ws:start:WikiTextHeadingRule:16:<h1> --><h1 id="toc8"><a name="Music"></a><!-- ws:end:WikiTextHeadingRule:16 -->Music</h1> <br /> <a class="wiki_link_ext" href="http://sethares.engr.wisc.edu/mp3s/PagansRevenge.mp3" rel="nofollow">Pagan's Revenge</a> by Bill Sethares (synthetic gamelan)<br /> <a class="wiki_link_ext" href="http://www.akjmusic.com/audio/i_dream_of_tibet.mp3" rel="nofollow">I dream of Tibet</a> by <a class="wiki_link_ext" href="http://www.akjmusic.com/works.html" rel="nofollow">Aaron K. Johnson</a> (electronic swirlies)<br /> <a class="wiki_link_ext" href="http://micro.soonlabel.com/gene_ward_smith/Others/Walker/Seven%20Equal%20Trio.mp3" rel="nofollow">Seven Equal Trio</a> by <a class="wiki_link_ext" href="http://robertinventor.tripod.com/tunes/tunes.htm#7_equal_trio" rel="nofollow">Robert Walker</a> ((synth) violin, viola, glockenspiel)<br /> <a class="wiki_link_ext" href="http://micro.soonlabel.com/gene_ward_smith/Others/Hunt/7ET.mp3" rel="nofollow">Two-part Invention in 7TET</a> by <a class="wiki_link_ext" href="http://www.h-pi.com/musicFiles.html" rel="nofollow">Aaron Hunt</a><br /> <a class="wiki_link_ext" href="http://www.uvnitr.cz/flaoyg/flao_yg/pavouci.html" rel="nofollow">Pavouci</a>, <a class="wiki_link_ext" href="http://www.uvnitr.cz/flaoyg/flao_yg/kelt.html" rel="nofollow">Kelt</a> by Milan Guštar<br /> <a class="wiki_link_ext" href="http://www.seraph.it/dep/det/7edo%20dance.mp3" rel="nofollow">7edo Dance</a> by Carlo Serafini<br /> <a class="wiki_link_ext" href="http://micro.soonlabel.com/gene_ward_smith/Others/Winchester/06%20-%206.%207%20octave.mp3" rel="nofollow">Comets Over Flatland 6</a> by <a class="wiki_link" href="/Randy%20Winchester">Randy Winchester</a><br /> <a class="wiki_link_ext" href="http://media.soundcloud.com/stream/IUcgFYhtu3Rk?stream_token=4QIvd" rel="nofollow">Sävelmä</a> by <a class="wiki_link_ext" href="http://soundcloud.com/juhani-nuorvala/s-velm-long-version" rel="nofollow">Juhani Nuorvala</a><br /> <br /> <!-- ws:start:WikiTextHeadingRule:18:<h1> --><h1 id="toc9"><a name="Commas"></a><!-- ws:end:WikiTextHeadingRule:18 -->Commas</h1> 7 EDO tempers out the following commas. (Note: This assumes val < 7 11 16 20 24 26 |.)<br /> <br /> <table class="wiki_table"> <tr> <th>Comma<br /> </th> <th>Monzo<br /> </th> <th>Cents<br /> </th> <th>Name 1<br /> </th> <th>Name 2<br /> </th> <th>Name 3<br /> </th> </tr> <tr> <td style="text-align: center;">2187/2048<br /> </td> <td>| -11 7 ><br /> </td> <td style="text-align: right;">113.69<br /> </td> <td style="text-align: center;">Apotome<br /> </td> <td style="text-align: center;"><br /> </td> <td style="text-align: center;"><br /> </td> </tr> <tr> <td style="text-align: center;">135/128<br /> </td> <td>| -7 3 1 ><br /> </td> <td style="text-align: right;">92.18<br /> </td> <td style="text-align: center;">Major Chroma<br /> </td> <td style="text-align: center;">Major Limma<br /> </td> <td style="text-align: center;">Pelogic Comma<br /> </td> </tr> <tr> <td style="text-align: center;">250/243<br /> </td> <td>| 1 -5 3 ><br /> </td> <td style="text-align: right;">49.17<br /> </td> <td style="text-align: center;">Maximal Diesis<br /> </td> <td style="text-align: center;">Porcupine Comma<br /> </td> <td style="text-align: center;"><br /> </td> </tr> <tr> <td style="text-align: center;">20000/19683<br /> </td> <td>| 5 -9 4 ><br /> </td> <td style="text-align: right;">27.66<br /> </td> <td style="text-align: center;">Minimal Diesis<br /> </td> <td style="text-align: center;">Tetracot Comma<br /> </td> <td style="text-align: center;"><br /> </td> </tr> <tr> <td style="text-align: center;">81/80<br /> </td> <td>| -4 4 -1 ><br /> </td> <td style="text-align: right;">21.51<br /> </td> <td style="text-align: center;">Syntonic Comma<br /> </td> <td style="text-align: center;">Didymos Comma<br /> </td> <td style="text-align: center;">Meantone Comma<br /> </td> </tr> <tr> <td style="text-align: center;">1600000/1594323<br /> </td> <td>| 9 -13 5 ><br /> </td> <td style="text-align: right;">6.15<br /> </td> <td style="text-align: center;">Amity Comma<br /> </td> <td style="text-align: center;"><br /> </td> <td style="text-align: center;"><br /> </td> </tr> <tr> <td style="text-align: center;">36/35<br /> </td> <td>| 2 2 -1 -1 ><br /> </td> <td style="text-align: right;">48.77<br /> </td> <td style="text-align: center;">Septimal Quarter Tone<br /> </td> <td style="text-align: center;"><br /> </td> <td style="text-align: center;"><br /> </td> </tr> <tr> <td style="text-align: center;">525/512<br /> </td> <td>| -9 1 2 1 ><br /> </td> <td style="text-align: right;">43.41<br /> </td> <td style="text-align: center;">Avicennma<br /> </td> <td style="text-align: center;">Avicenna's Enharmonic Diesis<br /> </td> <td style="text-align: center;"><br /> </td> </tr> <tr> <td style="text-align: center;">64/63<br /> </td> <td>| 6 -2 0 -1 ><br /> </td> <td style="text-align: right;">27.26<br /> </td> <td style="text-align: center;">Septimal Comma<br /> </td> <td style="text-align: center;">Archytas' Comma<br /> </td> <td style="text-align: center;">Leipziger Komma<br /> </td> </tr> <tr> <td style="text-align: center;">875/864<br /> </td> <td>| -5 -3 3 1 ><br /> </td> <td style="text-align: right;">21.90<br /> </td> <td style="text-align: center;">Keema<br /> </td> <td style="text-align: center;"><br /> </td> <td style="text-align: center;"><br /> </td> </tr> <tr> <td style="text-align: center;">5120/5103<br /> </td> <td>| 10 -6 1 -1 ><br /> </td> <td style="text-align: right;">5.76<br /> </td> <td style="text-align: center;">Hemifamity<br /> </td> <td style="text-align: center;"><br /> </td> <td style="text-align: center;"><br /> </td> </tr> <tr> <td style="text-align: center;">6144/6125<br /> </td> <td>| 11 1 -3 -2 ><br /> </td> <td style="text-align: right;">5.36<br /> </td> <td style="text-align: center;">Porwell<br /> </td> <td style="text-align: center;"><br /> </td> <td style="text-align: center;"><br /> </td> </tr> <tr> <td style="text-align: center;">4375/4374<br /> </td> <td>| -1 -7 4 1 ><br /> </td> <td style="text-align: right;">0.40<br /> </td> <td style="text-align: center;">Ragisma<br /> </td> <td style="text-align: center;"><br /> </td> <td style="text-align: center;"><br /> </td> </tr> <tr> <td style="text-align: center;">394839/394762<br /> </td> <td>| 47 -7 -7 -7 ><br /> </td> <td style="text-align: right;">0.34<br /> </td> <td style="text-align: center;">Akjaysma<br /> </td> <td style="text-align: center;">5\7 Octave Comma<br /> </td> <td style="text-align: center;"><br /> </td> </tr> <tr> <td style="text-align: center;">100/99<br /> </td> <td>| 2 -2 2 0 -1 ><br /> </td> <td style="text-align: right;">17.40<br /> </td> <td style="text-align: center;">Ptolemisma<br /> </td> <td style="text-align: center;"><br /> </td> <td style="text-align: center;"><br /> </td> </tr> <tr> <td style="text-align: center;">121/120<br /> </td> <td>| -3 -1 -1 0 2 ><br /> </td> <td style="text-align: right;">14.37<br /> </td> <td style="text-align: center;">Biyatisma<br /> </td> <td style="text-align: center;"><br /> </td> <td style="text-align: center;"><br /> </td> </tr> <tr> <td style="text-align: center;">176/175<br /> </td> <td>| 4 0 -2 -1 1 ><br /> </td> <td style="text-align: right;">9.86<br /> </td> <td style="text-align: center;">Valinorsma<br /> </td> <td style="text-align: center;"><br /> </td> <td style="text-align: center;"><br /> </td> </tr> <tr> <td style="text-align: center;">65536/65219<br /> </td> <td>| 16 0 0 -2 -3 ><br /> </td> <td style="text-align: right;">8.39<br /> </td> <td style="text-align: center;">Orgonisma<br /> </td> <td style="text-align: center;"><br /> </td> <td style="text-align: center;"><br /> </td> </tr> <tr> <td style="text-align: center;">243/242<br /> </td> <td>| -1 5 0 0 -2 ><br /> </td> <td style="text-align: right;">7.14<br /> </td> <td style="text-align: center;">Rastma<br /> </td> <td style="text-align: center;"><br /> </td> <td style="text-align: center;"><br /> </td> </tr> <tr> <td style="text-align: center;">385/384<br /> </td> <td>| -7 -1 1 1 1 ><br /> </td> <td style="text-align: right;">4.50<br /> </td> <td style="text-align: center;">Keenanisma<br /> </td> <td style="text-align: center;"><br /> </td> <td style="text-align: center;"><br /> </td> </tr> <tr> <td style="text-align: center;">4000/3993<br /> </td> <td>| 5 -1 3 0 -3 ><br /> </td> <td style="text-align: right;">3.03<br /> </td> <td style="text-align: center;">Wizardharry<br /> </td> <td style="text-align: center;"><br /> </td> <td style="text-align: center;"><br /> </td> </tr> </table> </body></html>