MOS scale: Difference between revisions

Wikispaces>genewardsmith
**Imported revision 143392517 - Original comment: **
Wikispaces>genewardsmith
**Imported revision 143411365 - 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>2010-05-20 02:39:36 UTC</tt>.<br>
: This revision was by author [[User:genewardsmith|genewardsmith]] and made on <tt>2010-05-20 05:28:45 UTC</tt>.<br>
: The original revision id was <tt>143392517</tt>.<br>
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: The revision comment was: <tt></tt><br>
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Yet another way of classifying MOS is via [[http://en.wikipedia.org/wiki/Minkowski%27s_question_mark_function|Minkowski's ? function]]. Here ?(x) is a continuous increasing function from the real numbers to the real numbers which has some peculiar properties, one being that it sends rational numbers to [[http://en.wikipedia.org/wiki/Dyadic_rational|dyadic rationals]]. Hence if q is a rational number 0 &lt; q &lt; 1 in use in the mediant system of classifying MOS, r = ?(q) = A/2^n will be a dyadic rational number which can also be used. Note that the ? function is invertible, and it and its inverse function, the Box function, have code given for them in the algorithms section at the bottom of the article.
Yet another way of classifying MOS is via [[http://en.wikipedia.org/wiki/Minkowski%27s_question_mark_function|Minkowski's ? function]]. Here ?(x) is a continuous increasing function from the real numbers to the real numbers which has some peculiar properties, one being that it sends rational numbers to [[http://en.wikipedia.org/wiki/Dyadic_rational|dyadic rationals]]. Hence if q is a rational number 0 &lt; q &lt; 1 in use in the mediant system of classifying MOS, r = ?(q) = A/2^n will be a dyadic rational number which can also be used. Note that the ? function is invertible, and it and its inverse function, the Box function, have code given for them in the algorithms section at the bottom of the article.


The integer n in the denominator of r (with A assumed to be odd) is the order (or n+1 is, according to some sources) of q in the [[http://en.wikipedia.org/wiki/Stern%E2%80%93Brocot_tree|Stern-Brocot tree]]. The two neighboring numbers of order n+1, which will be Box(r - 2^(-n-1) and Box(r + 2^(-n-1)) can also be expressed in terms of the ? and Box functions. If r represents a MOS, the range of possible values for a generator of the MOS will be Box(r) &lt; g &lt; Box(r + 2^(-n)). So, for example, the MOS denoted by 3/2048 will be between Box(3/2048) and Box(4/2048), which means that 2/11 &lt; g &lt; 1/10.
The integer n in the denominator of r (with A assumed to be odd) is the order (or n+1 is, according to some sources) of q in the [[http://en.wikipedia.org/wiki/Stern%E2%80%93Brocot_tree|Stern-Brocot tree]]. The two neighboring numbers of order n+1, which define the range of propriety, can also be expressed in terms of the ? and Box functions as Box(r - 2^(-n-1) and Box(r + 2^(-n-1)). If r represents a MOS, the range of possible values for a generator of the MOS will be Box(r) &lt; g &lt; Box(r + 2^(-n)), and the proper generators will be Box(r) &lt; g &lt; Box(r + 2^(-n-1)). So, for example, the MOS denoted by 3/2048 will be between Box(3/2048) and Box(4/2048), which means that 2/21 &lt; g &lt; 1/10, and will be proper if 2/21 &lt; g &lt; 3/31. Hence 7/72, a generator for miracle temperament, will define a MOS but it will not be proper since 7/72 &gt; 3/31 = Box(3/2048 + 1/4096)).


===Names for MOS===
===Names for MOS===
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Yet another way of classifying MOS is via &lt;a class="wiki_link_ext" href="http://en.wikipedia.org/wiki/Minkowski%27s_question_mark_function" rel="nofollow"&gt;Minkowski's ? function&lt;/a&gt;. Here ?(x) is a continuous increasing function from the real numbers to the real numbers which has some peculiar properties, one being that it sends rational numbers to &lt;a class="wiki_link_ext" href="http://en.wikipedia.org/wiki/Dyadic_rational" rel="nofollow"&gt;dyadic rationals&lt;/a&gt;. Hence if q is a rational number 0 &amp;lt; q &amp;lt; 1 in use in the mediant system of classifying MOS, r = ?(q) = A/2^n will be a dyadic rational number which can also be used. Note that the ? function is invertible, and it and its inverse function, the Box function, have code given for them in the algorithms section at the bottom of the article.&lt;br /&gt;
Yet another way of classifying MOS is via &lt;a class="wiki_link_ext" href="http://en.wikipedia.org/wiki/Minkowski%27s_question_mark_function" rel="nofollow"&gt;Minkowski's ? function&lt;/a&gt;. Here ?(x) is a continuous increasing function from the real numbers to the real numbers which has some peculiar properties, one being that it sends rational numbers to &lt;a class="wiki_link_ext" href="http://en.wikipedia.org/wiki/Dyadic_rational" rel="nofollow"&gt;dyadic rationals&lt;/a&gt;. Hence if q is a rational number 0 &amp;lt; q &amp;lt; 1 in use in the mediant system of classifying MOS, r = ?(q) = A/2^n will be a dyadic rational number which can also be used. Note that the ? function is invertible, and it and its inverse function, the Box function, have code given for them in the algorithms section at the bottom of the article.&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
The integer n in the denominator of r (with A assumed to be odd) is the order (or n+1 is, according to some sources) of q in the &lt;a class="wiki_link_ext" href="http://en.wikipedia.org/wiki/Stern%E2%80%93Brocot_tree" rel="nofollow"&gt;Stern-Brocot tree&lt;/a&gt;. The two neighboring numbers of order n+1, which will be Box(r - 2^(-n-1) and Box(r + 2^(-n-1)) can also be expressed in terms of the ? and Box functions. If r represents a MOS, the range of possible values for a generator of the MOS will be Box(r) &amp;lt; g &amp;lt; Box(r + 2^(-n)). So, for example, the MOS denoted by 3/2048 will be between Box(3/2048) and Box(4/2048), which means that 2/11 &amp;lt; g &amp;lt; 1/10.&lt;br /&gt;
The integer n in the denominator of r (with A assumed to be odd) is the order (or n+1 is, according to some sources) of q in the &lt;a class="wiki_link_ext" href="http://en.wikipedia.org/wiki/Stern%E2%80%93Brocot_tree" rel="nofollow"&gt;Stern-Brocot tree&lt;/a&gt;. The two neighboring numbers of order n+1, which define the range of propriety, can also be expressed in terms of the ? and Box functions as Box(r - 2^(-n-1) and Box(r + 2^(-n-1)). If r represents a MOS, the range of possible values for a generator of the MOS will be Box(r) &amp;lt; g &amp;lt; Box(r + 2^(-n)), and the proper generators will be Box(r) &amp;lt; g &amp;lt; Box(r + 2^(-n-1)). So, for example, the MOS denoted by 3/2048 will be between Box(3/2048) and Box(4/2048), which means that 2/21 &amp;lt; g &amp;lt; 1/10, and will be proper if 2/21 &amp;lt; g &amp;lt; 3/31. Hence 7/72, a generator for miracle temperament, will define a MOS but it will not be proper since 7/72 &amp;gt; 3/31 = Box(3/2048 + 1/4096)).&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
&lt;!-- ws:start:WikiTextHeadingRule:8:&amp;lt;h3&amp;gt; --&gt;&lt;h3 id="toc4"&gt;&lt;a name="MOS scales-Classification of MOS-Names for MOS"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:8 --&gt;Names for MOS&lt;/h3&gt;
&lt;!-- ws:start:WikiTextHeadingRule:8:&amp;lt;h3&amp;gt; --&gt;&lt;h3 id="toc4"&gt;&lt;a name="MOS scales-Classification of MOS-Names for MOS"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:8 --&gt;Names for MOS&lt;/h3&gt;