MOS rhythm: Difference between revisions

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<h2>IMPORTED REVISION FROM WIKISPACES</h2>
== Assumptions ==
This is an imported revision from Wikispaces. The revision metadata is included below for reference:<br>
Assume, for now, that a rhythm is specified as a set of pulses within an interval of time. Assume that a pulse is an instant of attack. Call the total interval of time a ''period''. '''Cyclical rhythms'' as defined here are distinguished by the exact spacing of pulses within a period; the tempo or tempo change of the period is not (yet) relevant to the cyclical rhythm. In our examples, the magnitude of the duration of the period will remain fixed.
: This revision was by author [[User:xenjacob|xenjacob]] and made on <tt>2009-01-18 18:06:47 UTC</tt>.<br>
 
: The original revision id was <tt>53937546</tt>.<br>
The durations in cyclical rhythms are specified not in ''absolute'' terms of time interval (minutes, seconds, beats of a metronome), but ''relative'' to the period, and thus expressed as a (unitless) proportion. For example, '1/2' (or '0.5') will represent a duration (interval of time) of exactly half the duration of the period.
: 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>
We are concerned with durations that are shorter than the duration of the period; i.e., greater than or equal to zero (no interval) and less than one (period). We can easily convert numbers outside that range by adding or subtracting 1 until they are in the range. This is tantamount to using a [https://en.wikipedia.org/wiki/Modular_arithmetic Modular arithmetic] with a modulus of 1. (Clocks and twelve-tone theory use a modulus of 12.)
<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">=Assumptions=  
Assume, for now, that a rhythm is specified as a set of pulses within an interval of time. Assume that a pulse is an instant of attack. Call the total interval of time a &lt;span class="Apple-style-span"&gt;//period//&lt;/span&gt;. 'MOS rhythms' as defined here are distinguished by the exact spacing of pulses within a period; the tempo or tempo change of the period is not (yet) relevant to the MOS rhythm. In our examples, the magnitude of the duration of the period will remain fixed.
The durations in MOS rhythms are specified not in &lt;span class="Apple-style-span"&gt;//absolute//&lt;/span&gt; terms of time interval (minutes, seconds, beats of a metronome), but &lt;span class="Apple-style-span"&gt;//relative//&lt;/span&gt; to the period, and thus expressed as a (unitless) proportion. For example, '1/2' (or '0.5') will represent a duration (interval of time) of exactly half the duration of the period.
We are concerned with durations that are shorter than the duration of the period; i.e., greater than or equal to zero (no interval) and less than one (period). We can easily convert numbers outside that range by adding or subtracting 1 until they are in the range. (This is tantamount to using [[http://en.wikipedia.org/wiki/Modular_arithmetic|Modular arithmetic]] with a modulus of 1.)
We can use the metaphor of a timeline, assuming that a line segment (representing a period) can be broken up into smaller line segments (durations or intervals) as delineated by the placement of points (pulses):
We can use the metaphor of a timeline, assuming that a line segment (representing a period) can be broken up into smaller line segments (durations or intervals) as delineated by the placement of points (pulses):


[[image:mr_line.png align="center"]]
[[File:mr_line.png|alt=mr_line.png|mr_line.png]]Furthermore, we can emphasize the cyclical nature of our arithmetic if we bend the line segment into a circle (drawing a point at the top for 0/1):
Furthermore, we can emphasize the cyclical nature of our arithmetic if we bend the line segment into a circle (drawing a point at the top for 0/1):
 
[[image:mr_cycle.png align="center"]]</pre></div>
[[File:mr_cycle.png|alt=mr_cycle.png|mr_cycle.png]]When we want to refer to an interval ''from zero'', which also specifies a single pulse within a period, we will use unadorned expressions (e.g. ''a'' and ''1-a''). When we want to talk about an interval ''from anywhere'', emphasizing only the magnitude of it, we will enclose it within vertical slashes | |
<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;MOS Rhythm Tutorial&lt;/title&gt;&lt;/head&gt;&lt;body&gt;&lt;!-- ws:start:WikiTextHeadingRule:0:&amp;lt;h1&amp;gt; --&gt;&lt;h1 id="toc0"&gt;&lt;a name="Assumptions"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:0 --&gt;Assumptions&lt;/h1&gt;
== Generators ==
Assume, for now, that a rhythm is specified as a set of pulses within an interval of time. Assume that a pulse is an instant of attack. Call the total interval of time a &lt;span class="Apple-style-span"&gt;&lt;em&gt;period&lt;/em&gt;&lt;/span&gt;. 'MOS rhythms' as defined here are distinguished by the exact spacing of pulses within a period; the tempo or tempo change of the period is not (yet) relevant to the MOS rhythm. In our examples, the magnitude of the duration of the period will remain fixed.&lt;br /&gt;
Cyclical rhythms are calculated by taking ''multiples'' of a single interval, called the ''generating interval'' or ''generator''. When one interval is called a ''generator'' interval relative to a period, a ''family'' of cyclical rhythms is specified. When how many multiples and which multiples are specified, a single cyclical rhythm is specified.
The durations in MOS rhythms are specified not in &lt;span class="Apple-style-span"&gt;&lt;em&gt;absolute&lt;/em&gt;&lt;/span&gt; terms of time interval (minutes, seconds, beats of a metronome), but &lt;span class="Apple-style-span"&gt;&lt;em&gt;relative&lt;/em&gt;&lt;/span&gt; to the period, and thus expressed as a (unitless) proportion. For example, '1/2' (or '0.5') will represent a duration (interval of time) of exactly half the duration of the period.&lt;br /&gt;
 
We are concerned with durations that are shorter than the duration of the period; i.e., greater than or equal to zero (no interval) and less than one (period). We can easily convert numbers outside that range by adding or subtracting 1 until they are in the range. (This is tantamount to using &lt;a class="wiki_link_ext" href="http://en.wikipedia.org/wiki/Modular_arithmetic" rel="nofollow"&gt;Modular arithmetic&lt;/a&gt; with a modulus of 1.)&lt;br /&gt;
== History ==
We can use the metaphor of a timeline, assuming that a line segment (representing a period) can be broken up into smaller line segments (durations or intervals) as delineated by the placement of points (pulses):&lt;br /&gt;
David Canright was the first to suggest Fibonacci Rhythms in 1/1. This led to Kraig Grady to be the first to apply MOS patterns to rhythms. Two papers on the subject can be found here:
&lt;br /&gt;
 
&lt;!-- ws:start:WikiTextLocalImageRule:2:&amp;lt;div style=&amp;quot;text-align: center&amp;quot;&amp;gt;&amp;lt;img src=&amp;quot;/file/view/mr_line.png/54241800/mr_line.png&amp;quot; alt=&amp;quot;&amp;quot; title=&amp;quot;&amp;quot; /&amp;gt;&amp;lt;/div&amp;gt; --&gt;&lt;div style="text-align: center"&gt;&lt;img src="/file/view/mr_line.png/54241800/mr_line.png" alt="mr_line.png" title="mr_line.png" /&gt;&lt;/div&gt;&lt;!-- ws:end:WikiTextLocalImageRule:2 --&gt;Furthermore, we can emphasize the cyclical nature of our arithmetic if we bend the line segment into a circle (drawing a point at the top for 0/1):&lt;br /&gt;
* [http://anaphoria.com/hora.pdf A Rhythmic Application of the Horagrams] from ''[[Xenharmonikon]] 16''
&lt;!-- ws:start:WikiTextLocalImageRule:3:&amp;lt;div style=&amp;quot;text-align: center&amp;quot;&amp;gt;&amp;lt;img src=&amp;quot;/file/view/mr_cycle.png/54241802/mr_cycle.png&amp;quot; alt=&amp;quot;&amp;quot; title=&amp;quot;&amp;quot; /&amp;gt;&amp;lt;/div&amp;gt; --&gt;&lt;div style="text-align: center"&gt;&lt;img src="/file/view/mr_cycle.png/54241802/mr_cycle.png" alt="mr_cycle.png" title="mr_cycle.png" /&gt;&lt;/div&gt;&lt;!-- ws:end:WikiTextLocalImageRule:3 --&gt;&lt;/body&gt;&lt;/html&gt;</pre></div>
* [http://anaphoria.com/horo2.pdf More on Horogram Rhythms]
 
[[Category:Non-scale applications of MOS]]
[[Category:Rhythm]]
[[Category:todo:expand]]
 
== See also ==
 
* [[Gallery of MOS patterns]]