Monzos and interval space: Difference between revisions

Wikispaces>mbattaglia1
**Imported revision 250543914 - Original comment: **
Wikispaces>clumma
**Imported revision 250559138 - Original comment: Reverted to Jun 25, 2011 5:32 pm: reverting to last edit by xenjacob**
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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:mbattaglia1|mbattaglia1]] and made on <tt>2011-09-03 20:01:03 UTC</tt>.<br>
: This revision was by author [[User:clumma|clumma]] and made on <tt>2011-09-03 22:53:36 UTC</tt>.<br>
: The original revision id was <tt>250543914</tt>.<br>
: The original revision id was <tt>250559138</tt>.<br>
: The revision comment was: <tt></tt><br>
: The revision comment was: <tt>Reverted to Jun 25, 2011 5:32 pm: reverting to last edit by xenjacob</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">=Abstract=
<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">A [[Harmonic Limit|p-limit]] rational number q can by definition be factored into primes of size less than or equal to p, giving
A monzo is the counterpart to a val. Much like vals allow us to express the way that prime intervals are mapped within an EDO, a monzo allows us to express how any "composite" interval is represented in terms of those simpler prime intervals. They are typically written using the notation |a b c d e f ... &gt;, where the columns represent how the primes 2, 3, 5, 7, 11, 13, etc, in that order, contribute to the interval's prime factorization, up to some [[harmonic limit|prime limit]].
 
For example, the interval 15/8 can be thought of as having 5*3 in the numerator, and 2*2*2 in the denominator. This can be compactly represented by the expression 2^-3 * 3^1 * 5^1, which is exactly equal to 15/8. We construct the monzo by taking the exponent from each prime, in order, and placing them within the |.........&gt; brackets, hence yielding |-3 1 1&gt;.
 
Here are some common 5-limit monzos, for your reference:
3/2: |-1 1 0&gt;
5/4: |-2 0 1&gt;
9/8: |-3 2 0&gt;
81/80: |-4 4 -1&gt;
 
Here are a few 7-limit monzos:
7/4: |-2 0 0 1&gt;
7/6: |-1 -1 0 1&gt;
7/5: |0 0 -1 1&gt;
 
Monzos are important because they enable us to see how any JI interval "maps" onto a val. This mapping is expressed by writing the val and the monzo together, such as &lt;12 19 28|-4 4 -1&gt;. The mapping is extremely easily to calculate: simply multiply together each component in the same position on both sides of the line, and add the results together. This is perhaps best demonstrated by example:
 
&lt;12 19 28|-4 4 -1&gt; = (12*-4) + (19*4) + (28*1)&lt;span class="st"&gt; &amp;#61; &lt;/span&gt;0
 
In this case, the val &lt;12 19 28| is the [[patent val]] for 12-equal, and |-4 4 -1&gt; is 81/80, or the syntonic comma. The fact that &lt;12 19 28|-4 4 -1&gt; tells us that 81/80 is mapped to 0 steps in 12-equal - aka it's tempered out - which tells us that 12-equal is a meantone temperament. It is noteworthy that almost the entirety of western music, particularly western music composed for 12-equal or 12-tone well temperaments, is made possible by the above equation.
 
**In general: &lt;a b c|d e f&gt; = ad + be + cf**
 
=Mathematical Definition=
 
A [[Harmonic Limit|p-limit]] rational number q can by definition be factored into primes of size less than or equal to p, giving
[[math]]
[[math]]
q = 2^{e_2} \, 3^{e_3} \, 5^{e_5} \dotso p^{e_p}
q = 2^{e_2} \, 3^{e_3} \, 5^{e_5} \dotso p^{e_p}
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//see also [[Fractional monzos]], [[Vals and Tuning Space]]...//</pre></div>
//see also [[Fractional monzos]], [[Vals and Tuning Space]]...//</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;Monzos and Interval Space&lt;/title&gt;&lt;/head&gt;&lt;body&gt;&lt;!-- ws:start:WikiTextHeadingRule:4:&amp;lt;h1&amp;gt; --&gt;&lt;h1 id="toc0"&gt;&lt;a name="Abstract"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:4 --&gt;Abstract&lt;/h1&gt;
<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;Monzos and Interval Space&lt;/title&gt;&lt;/head&gt;&lt;body&gt;A &lt;a class="wiki_link" href="/Harmonic%20Limit"&gt;p-limit&lt;/a&gt; rational number q can by definition be factored into primes of size less than or equal to p, giving&lt;br /&gt;
A monzo is the counterpart to a val. Much like vals allow us to express the way that prime intervals are mapped within an EDO, a monzo allows us to express how any &amp;quot;composite&amp;quot; interval is represented in terms of those simpler prime intervals. They are typically written using the notation |a b c d e f ... &amp;gt;, where the columns represent how the primes 2, 3, 5, 7, 11, 13, etc, in that order, contribute to the interval's prime factorization, up to some &lt;a class="wiki_link" href="/harmonic%20limit"&gt;prime limit&lt;/a&gt;.&lt;br /&gt;
&lt;br /&gt;
For example, the interval 15/8 can be thought of as having 5*3 in the numerator, and 2*2*2 in the denominator. This can be compactly represented by the expression 2^-3 * 3^1 * 5^1, which is exactly equal to 15/8. We construct the monzo by taking the exponent from each prime, in order, and placing them within the |.........&amp;gt; brackets, hence yielding |-3 1 1&amp;gt;.&lt;br /&gt;
&lt;br /&gt;
Here are some common 5-limit monzos, for your reference:&lt;br /&gt;
3/2: |-1 1 0&amp;gt;&lt;br /&gt;
5/4: |-2 0 1&amp;gt;&lt;br /&gt;
9/8: |-3 2 0&amp;gt;&lt;br /&gt;
81/80: |-4 4 -1&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Here are a few 7-limit monzos:&lt;br /&gt;
7/4: |-2 0 0 1&amp;gt;&lt;br /&gt;
7/6: |-1 -1 0 1&amp;gt;&lt;br /&gt;
7/5: |0 0 -1 1&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Monzos are important because they enable us to see how any JI interval &amp;quot;maps&amp;quot; onto a val. This mapping is expressed by writing the val and the monzo together, such as &amp;lt;12 19 28|-4 4 -1&amp;gt;. The mapping is extremely easily to calculate: simply multiply together each component in the same position on both sides of the line, and add the results together. This is perhaps best demonstrated by example:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;12 19 28|-4 4 -1&amp;gt; = (12*-4) + (19*4) + (28*1)&lt;span class="st"&gt; &amp;#61; &lt;/span&gt;0&lt;br /&gt;
&lt;br /&gt;
In this case, the val &amp;lt;12 19 28| is the &lt;a class="wiki_link" href="/patent%20val"&gt;patent val&lt;/a&gt; for 12-equal, and |-4 4 -1&amp;gt; is 81/80, or the syntonic comma. The fact that &amp;lt;12 19 28|-4 4 -1&amp;gt; tells us that 81/80 is mapped to 0 steps in 12-equal - aka it's tempered out - which tells us that 12-equal is a meantone temperament. It is noteworthy that almost the entirety of western music, particularly western music composed for 12-equal or 12-tone well temperaments, is made possible by the above equation.&lt;br /&gt;
&lt;br /&gt;
&lt;strong&gt;In general: &amp;lt;a b c|d e f&amp;gt; = ad + be + cf&lt;/strong&gt;&lt;br /&gt;
&lt;br /&gt;
&lt;!-- ws:start:WikiTextHeadingRule:6:&amp;lt;h1&amp;gt; --&gt;&lt;h1 id="toc1"&gt;&lt;a name="Mathematical Definition"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:6 --&gt;Mathematical Definition&lt;/h1&gt;
&lt;br /&gt;
A &lt;a class="wiki_link" href="/Harmonic%20Limit"&gt;p-limit&lt;/a&gt; rational number q can by definition be factored into primes of size less than or equal to p, giving&lt;br /&gt;
&lt;!-- ws:start:WikiTextMathRule:0:
&lt;!-- ws:start:WikiTextMathRule:0:
[[math]]&amp;lt;br/&amp;gt;
[[math]]&amp;lt;br/&amp;gt;
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and if the coordinates are the weighted interval space coordinates, then the TE norm is the &lt;a class="wiki_link_ext" href="http://mathworld.wolfram.com/L2-Norm.html" rel="nofollow"&gt;standard Euclidean, or L2, norm&lt;/a&gt;.&lt;br /&gt;
and if the coordinates are the weighted interval space coordinates, then the TE norm is the &lt;a class="wiki_link_ext" href="http://mathworld.wolfram.com/L2-Norm.html" rel="nofollow"&gt;standard Euclidean, or L2, norm&lt;/a&gt;.&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
&lt;!-- ws:start:WikiTextHeadingRule:8:&amp;lt;h2&amp;gt; --&gt;&lt;h2 id="toc2"&gt;&lt;a name="Mathematical Definition-Example"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:8 --&gt;Example&lt;/h2&gt;
&lt;!-- ws:start:WikiTextHeadingRule:4:&amp;lt;h2&amp;gt; --&gt;&lt;h2 id="toc0"&gt;&lt;a name="x-Example"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:4 --&gt;Example&lt;/h2&gt;
  The 5-limit interval 16/15 factors as 2^4 3^(-1) 5^(-1), so it has a monzo representation of |4 -1 -1&amp;gt;. In weighted coordinates, that becomes |4 -log2(3) -log2(5)&amp;gt;, approximately |4 -1.585 -2.322&amp;gt;. The TE norm is therefore sqrt(1^2 + log2(3)^2 + log2(5)^2) ~ sqrt(23.903) = 4.889.&lt;br /&gt;
  The 5-limit interval 16/15 factors as 2^4 3^(-1) 5^(-1), so it has a monzo representation of |4 -1 -1&amp;gt;. In weighted coordinates, that becomes |4 -log2(3) -log2(5)&amp;gt;, approximately |4 -1.585 -2.322&amp;gt;. The TE norm is therefore sqrt(1^2 + log2(3)^2 + log2(5)^2) ~ sqrt(23.903) = 4.889.&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
&lt;em&gt;see also &lt;a class="wiki_link" href="/Fractional%20monzos"&gt;Fractional monzos&lt;/a&gt;, &lt;a class="wiki_link" href="/Vals%20and%20Tuning%20Space"&gt;Vals and Tuning Space&lt;/a&gt;...&lt;/em&gt;&lt;/body&gt;&lt;/html&gt;</pre></div>
&lt;em&gt;see also &lt;a class="wiki_link" href="/Fractional%20monzos"&gt;Fractional monzos&lt;/a&gt;, &lt;a class="wiki_link" href="/Vals%20and%20Tuning%20Space"&gt;Vals and Tuning Space&lt;/a&gt;...&lt;/em&gt;&lt;/body&gt;&lt;/html&gt;</pre></div>