Prime number: Difference between revisions
Wikispaces>hstraub **Imported revision 240196903 - 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:hstraub|hstraub]] and made on <tt>2011-07-06 10: | : This revision was by author [[User:hstraub|hstraub]] and made on <tt>2011-07-06 10:31:40 UTC</tt>.<br> | ||
: The original revision id was <tt> | : The original revision id was <tt>240198529</tt>.<br> | ||
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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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<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">=Some thoughts about prime numbers in [[EDO]]s= | <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">=Some thoughts about prime numbers in [[EDO]]s= | ||
Whether a number n is prime or not has quite vital consequences for the properties of the corresponding n-[[edo]], especially for lower | Whether a number n is prime or not has quite vital consequences for the properties of the corresponding n-[[edo|EDO]], especially for lower values of n. | ||
* If the octave is divided into a prime number of equal parts, there is **no fully symmetric chord**, such as the diminished seventh chord in [[12edo]]. | |||
If the octave is divided into a prime number of equal parts, there is no fully symmetric chord, such as the diminished seventh chord in [[12edo]]. | * There is also (besides the full scale of all notes of the edo) **no absolutely uniform scale**, like the wholetone scale in 12edo. | ||
* Nor is there a thing like [[http://en.wikipedia.org/wiki/Modes_of_limited_transposition|modes of limited transpostion]], as used by the composer Olivier Messiaen. | |||
There is also (besides the full scale of all notes of the edo) no absolutely uniform scale, like the wholetone scale in 12edo. | |||
Nor is there a thing like [[http://en.wikipedia.org/wiki/Modes_of_limited_transposition|modes of limited transpostion]], as used by the composer Olivier Messiaen. | |||
For these or similar reasons, some musicians seem not to like prime EDOs (e.g. the makers of [[http://www.armodue.com/risorse.htm|Armodue]]). | For these or similar reasons, some musicians seem not to like prime EDOs (e.g. the makers of [[http://www.armodue.com/risorse.htm|Armodue]]). | ||
OTOH, primeness may be a desirable feature if you happen to want, e.g., a wholetone | OTOH, primeness may be a desirable feature if you happen to want, e.g., a wholetone scale that is **not** absolutely uniform. (In this case you might like [[19edo]], for example.) | ||
The larger the number n is, the less these points matter, since the difference between an **absolutely** uniform scale and an approximated, **nearly** uniform scale eventually become inaudible. | The larger the number n is, the less these points matter, since the difference between an **absolutely** uniform scale and an approximated, **nearly** uniform scale eventually become inaudible. | ||
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todo: add more useful things about prime numbers for musicians, composers, microtonalists, xenharmonicians, theorists here. XXX | todo: add more useful things about prime numbers for musicians, composers, microtonalists, xenharmonicians, theorists here. XXX | ||
==The first "Prime | ==The first "Prime EDOs"== | ||
Prime | Prime EDOs inherit most of its properties to its multiple EDOs. The children can often more, but they lose in handiness compared to their parents. | ||
[[2edo|2]], [[3edo|3]], [[5edo|5]], [[7edo|7]], [[11edo|11]], [[13edo|13]], [[17edo|17]], | [[2edo|2]], [[3edo|3]], [[5edo|5]], [[7edo|7]], [[11edo|11]], [[13edo|13]], [[17edo|17]], | ||
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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>prime numbers</title></head><body><!-- ws:start:WikiTextHeadingRule:0:&lt;h1&gt; --><h1 id="toc0"><a name="Some thoughts about prime numbers in EDOs"></a><!-- ws:end:WikiTextHeadingRule:0 -->Some thoughts about prime numbers in <a class="wiki_link" href="/EDO">EDO</a>s</h1> | <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>prime numbers</title></head><body><!-- ws:start:WikiTextHeadingRule:0:&lt;h1&gt; --><h1 id="toc0"><a name="Some thoughts about prime numbers in EDOs"></a><!-- ws:end:WikiTextHeadingRule:0 -->Some thoughts about prime numbers in <a class="wiki_link" href="/EDO">EDO</a>s</h1> | ||
<br /> | <br /> | ||
Whether a number n is prime or not has quite vital consequences for the properties of the corresponding n-<a class="wiki_link" href="/edo"> | Whether a number n is prime or not has quite vital consequences for the properties of the corresponding n-<a class="wiki_link" href="/edo">EDO</a>, especially for lower values of n.<br /> | ||
< | <ul><li>If the octave is divided into a prime number of equal parts, there is <strong>no fully symmetric chord</strong>, such as the diminished seventh chord in <a class="wiki_link" href="/12edo">12edo</a>.</li><li>There is also (besides the full scale of all notes of the edo) <strong>no absolutely uniform scale</strong>, like the wholetone scale in 12edo.</li><li>Nor is there a thing like <a class="wiki_link_ext" href="http://en.wikipedia.org/wiki/Modes_of_limited_transposition" rel="nofollow">modes of limited transpostion</a>, as used by the composer Olivier Messiaen.</li></ul><br /> | ||
If the octave is divided into a prime number of equal parts, there is no fully symmetric chord, such as the diminished seventh chord in <a class="wiki_link" href="/12edo">12edo</a>. < | |||
< | |||
There is also (besides the full scale of all notes of the edo) no absolutely uniform scale, like the wholetone scale in 12edo.< | |||
< | |||
Nor is there a thing like <a class="wiki_link_ext" href="http://en.wikipedia.org/wiki/Modes_of_limited_transposition" rel="nofollow">modes of limited transpostion</a>, as used by the composer Olivier Messiaen.< | |||
<br /> | |||
For these or similar reasons, some musicians seem not to like prime EDOs (e.g. the makers of <a class="wiki_link_ext" href="http://www.armodue.com/risorse.htm" rel="nofollow">Armodue</a>).<br /> | For these or similar reasons, some musicians seem not to like prime EDOs (e.g. the makers of <a class="wiki_link_ext" href="http://www.armodue.com/risorse.htm" rel="nofollow">Armodue</a>).<br /> | ||
<br /> | <br /> | ||
OTOH, primeness may be a desirable feature if you happen to want, e.g., a wholetone | OTOH, primeness may be a desirable feature if you happen to want, e.g., a wholetone scale that is <strong>not</strong> absolutely uniform. (In this case you might like <a class="wiki_link" href="/19edo">19edo</a>, for example.)<br /> | ||
<br /> | <br /> | ||
The larger the number n is, the less these points matter, since the difference between an <strong>absolutely</strong> uniform scale and an approximated, <strong>nearly</strong> uniform scale eventually become inaudible.<br /> | The larger the number n is, the less these points matter, since the difference between an <strong>absolutely</strong> uniform scale and an approximated, <strong>nearly</strong> uniform scale eventually become inaudible.<br /> | ||
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todo: add more useful things about prime numbers for musicians, composers, microtonalists, xenharmonicians, theorists here. XXX<br /> | todo: add more useful things about prime numbers for musicians, composers, microtonalists, xenharmonicians, theorists here. XXX<br /> | ||
<br /> | <br /> | ||
<!-- ws:start:WikiTextHeadingRule:2:&lt;h2&gt; --><h2 id="toc1"><a name="Some thoughts about prime numbers in EDOs-The first &quot;Prime | <!-- ws:start:WikiTextHeadingRule:2:&lt;h2&gt; --><h2 id="toc1"><a name="Some thoughts about prime numbers in EDOs-The first &quot;Prime EDOs&quot;"></a><!-- ws:end:WikiTextHeadingRule:2 -->The first &quot;Prime EDOs&quot;</h2> | ||
Prime | Prime EDOs inherit most of its properties to its multiple EDOs. The children can often more, but they lose in handiness compared to their parents.<br /> | ||
<br /> | <br /> | ||
<a class="wiki_link" href="/2edo">2</a>, <a class="wiki_link" href="/3edo">3</a>, <a class="wiki_link" href="/5edo">5</a>, <a class="wiki_link" href="/7edo">7</a>, <a class="wiki_link" href="/11edo">11</a>, <a class="wiki_link" href="/13edo">13</a>, <a class="wiki_link" href="/17edo">17</a>,<br /> | <a class="wiki_link" href="/2edo">2</a>, <a class="wiki_link" href="/3edo">3</a>, <a class="wiki_link" href="/5edo">5</a>, <a class="wiki_link" href="/7edo">7</a>, <a class="wiki_link" href="/11edo">11</a>, <a class="wiki_link" href="/13edo">13</a>, <a class="wiki_link" href="/17edo">17</a>,<br /> |