Andrew Heathwaite's MOS Investigations: Difference between revisions

Wikispaces>Andrew_Heathwaite
**Imported revision 270457072 - Original comment: **
Wikispaces>Andrew_Heathwaite
**Imported revision 270653882 - 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:Andrew_Heathwaite|Andrew_Heathwaite]] and made on <tt>2011-10-31 19:46:20 UTC</tt>.<br>
: This revision was by author [[User:Andrew_Heathwaite|Andrew_Heathwaite]] and made on <tt>2011-11-01 11:22:56 UTC</tt>.<br>
: The original revision id was <tt>270457072</tt>.<br>
: The original revision id was <tt>270653882</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>
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**3 2 5 3 3 3 3 .. -4 -3 -2 -1 0 1 _ _ _ _ _ _ _ 9**
**3 2 5 3 3 3 3 .. -4 -3 -2 -1 0 1 _ _ _ _ _ _ _ 9**


Did I miss any???</pre></div>
Update: Mike Battaglia has made a dedicated page for explaining these modes -- yay! -- see [[Porcupine Temperament Modal Harmony]].
 
=Orwell[9], meet Porcupine[7]=
 
I've done a little composing in Orwell[9], which, in 22edo, goes 3 2 3 2 3 2 3 2 2 (where L=3\22 and s=2\22), so I want to apply MODMOS to that. To make a MODMOS here, we alter a tone by a single degree of 22edo, same as we do in Porcupine[7]. This is our "chroma," and it's generated by taking L-s: so in 22edo we have 3\22-2\22=1\22. We wind up with either:
# A permutation of the four large and five small steps, eg. 3 3 2 2 3 2 3 2 2
## How many of these are there? Does anyone know a formula for finding the number of possible permutations when some of the items are interchangable? Here the question is, how many permutations can we make of 4 items of Type A and 5 items of Type B?
# A scale with three step sizes: large, small, and smaller, eg. 3 2 3 2 3 2 3 3 1
## In 22edo, our "smaller" step is the same as our "chroma" (which is the interval that we alter a tone by to produce a MODMOS, L-s). However, this is not the case in larger edos! Look at [[31edo]], where our initial scale is 4 3 4 3 4 3 4 3 3. Now our chroma is 4\31-3\31=1\31 and our "smaller" step is 2\31: 4 3 4 3 4 3 4 4 2! We get our "smaller" step by starting with s (3\31) and taking away a chroma (1\31), so we have 3\31-1\31=2\31.
## So what should we call the "smaller" interval in our scale? Maybe some kind of diminished something-or-another?
# A scale with four steps sizes: large, small, larger and smaller, eg. 4 1 3 2 3 2 3 2 2
## This is generated by starting with L and adding a chroma, so in 22edo it's 3\22+1\22=4\22. In 31edo, that would be 4\31+1\31=5\31, and the scale in question would be 5 2 4 3 4 3 4 3 3.
## So what should we call the "larger" step? Some kind of augmented something-or-another?
## Note that in 22edo, our "larger" step, 4\22, is the same as two of our small steps (2\22+2\22=4\22), even though we generated our "larger" step by adding a chroma to a large step (3\22+1\22). In 31edo, our "larger" step is NOT the same as two of our small steps (4\31+1\31=5\31 does not equal 3\31+3\31=6\31)!
 
So we can take advantage of the fact that two small steps in 22edo's Orwell[9] (2\22) make one "larger" step (4\22). If 9 tones is a few too many, we can turn some 2+2's into 4's. So for instance, the first example above goes:
 
3 3 2 2 3 2 3 2 2
3 3 4 3 2 3 4.
 
But check it out! 3 3 4 3 2 3 4 is a MODMOS of Porcupine[7]! Here's how we can get it by chromatically-altering Porcupine[7] one tone at a time:
 
3 3 3 3 3 3 4
3 3 4 2 3 3 4
3 3 4 3 2 3 4
 
And we see, not surprisingly, that this doesn't work the same way in 31edo.
 
Start with a MODMOS of Orwell[9]: 4 4 3 3 4 3 4 3 3
Combine small steps: 4 4 6 4 3 4 6
 
4 4 4 4 4 4 7 is as close as we can get to Porcupine[7], and it sure ain't the same. Our chroma (L-s) is 3\31, really different!
4 4 7 1 4 4 7
4 4 7 1 4 1 7
 
Not even close!</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;Andrew Heathwaite's MOS Investigations&lt;/title&gt;&lt;/head&gt;&lt;body&gt;Ok, this is a page for me, Andrew Heathwaite, to organize my thoughts and questions regarding &lt;a class="wiki_link" href="/MOSScales"&gt;Moment of Symmetry Scales&lt;/a&gt;.&lt;br /&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;Andrew Heathwaite's MOS Investigations&lt;/title&gt;&lt;/head&gt;&lt;body&gt;Ok, this is a page for me, Andrew Heathwaite, to organize my thoughts and questions regarding &lt;a class="wiki_link" href="/MOSScales"&gt;Moment of Symmetry Scales&lt;/a&gt;.&lt;br /&gt;
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&lt;strong&gt;3 2 5 3 3 3 3 .. -4 -3 -2 -1 0 1 _ _ _ _ _ _ _ 9&lt;/strong&gt;&lt;br /&gt;
&lt;strong&gt;3 2 5 3 3 3 3 .. -4 -3 -2 -1 0 1 _ _ _ _ _ _ _ 9&lt;/strong&gt;&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
Did I miss any???&lt;/body&gt;&lt;/html&gt;</pre></div>
Update: Mike Battaglia has made a dedicated page for explaining these modes -- yay! -- see &lt;a class="wiki_link" href="/Porcupine%20Temperament%20Modal%20Harmony"&gt;Porcupine Temperament Modal Harmony&lt;/a&gt;.&lt;br /&gt;
&lt;br /&gt;
&lt;!-- ws:start:WikiTextHeadingRule:8:&amp;lt;h1&amp;gt; --&gt;&lt;h1 id="toc4"&gt;&lt;a name="Orwell[9], meet Porcupine[7]"&gt;&lt;/a&gt;&lt;!-- ws:end:WikiTextHeadingRule:8 --&gt;Orwell[9], meet Porcupine[7]&lt;/h1&gt;
&lt;br /&gt;
I've done a little composing in Orwell[9], which, in 22edo, goes 3 2 3 2 3 2 3 2 2 (where L=3\22 and s=2\22), so I want to apply MODMOS to that. To make a MODMOS here, we alter a tone by a single degree of 22edo, same as we do in Porcupine[7]. This is our &amp;quot;chroma,&amp;quot; and it's generated by taking L-s: so in 22edo we have 3\22-2\22=1\22. We wind up with either:&lt;br /&gt;
&lt;ol&gt;&lt;li&gt;A permutation of the four large and five small steps, eg. 3 3 2 2 3 2 3 2 2&lt;ol&gt;&lt;li&gt;How many of these are there? Does anyone know a formula for finding the number of possible permutations when some of the items are interchangable? Here the question is, how many permutations can we make of 4 items of Type A and 5 items of Type B?&lt;/li&gt;&lt;/ol&gt;&lt;/li&gt;&lt;li&gt;A scale with three step sizes: large, small, and smaller, eg. 3 2 3 2 3 2 3 3 1&lt;ol&gt;&lt;li&gt;In 22edo, our &amp;quot;smaller&amp;quot; step is the same as our &amp;quot;chroma&amp;quot; (which is the interval that we alter a tone by to produce a MODMOS, L-s). However, this is not the case in larger edos! Look at &lt;a class="wiki_link" href="/31edo"&gt;31edo&lt;/a&gt;, where our initial scale is 4 3 4 3 4 3 4 3 3. Now our chroma is 4\31-3\31=1\31 and our &amp;quot;smaller&amp;quot; step is 2\31: 4 3 4 3 4 3 4 4 2! We get our &amp;quot;smaller&amp;quot; step by starting with s (3\31) and taking away a chroma (1\31), so we have 3\31-1\31=2\31.&lt;/li&gt;&lt;li&gt;So what should we call the &amp;quot;smaller&amp;quot; interval in our scale? Maybe some kind of diminished something-or-another?&lt;/li&gt;&lt;/ol&gt;&lt;/li&gt;&lt;li&gt;A scale with four steps sizes: large, small, larger and smaller, eg. 4 1 3 2 3 2 3 2 2&lt;ol&gt;&lt;li&gt;This is generated by starting with L and adding a chroma, so in 22edo it's 3\22+1\22=4\22. In 31edo, that would be 4\31+1\31=5\31, and the scale in question would be 5 2 4 3 4 3 4 3 3.&lt;/li&gt;&lt;li&gt;So what should we call the &amp;quot;larger&amp;quot; step? Some kind of augmented something-or-another?&lt;/li&gt;&lt;li&gt;Note that in 22edo, our &amp;quot;larger&amp;quot; step, 4\22, is the same as two of our small steps (2\22+2\22=4\22), even though we generated our &amp;quot;larger&amp;quot; step by adding a chroma to a large step (3\22+1\22). In 31edo, our &amp;quot;larger&amp;quot; step is NOT the same as two of our small steps (4\31+1\31=5\31 does not equal 3\31+3\31=6\31)!&lt;/li&gt;&lt;/ol&gt;&lt;/li&gt;&lt;/ol&gt;&lt;br /&gt;
So we can take advantage of the fact that two small steps in 22edo's Orwell[9] (2\22) make one &amp;quot;larger&amp;quot; step (4\22). If 9 tones is a few too many, we can turn some 2+2's into 4's. So for instance, the first example above goes:&lt;br /&gt;
&lt;br /&gt;
3 3 2 2 3 2 3 2 2 &lt;br /&gt;
3 3 4 3 2 3 4.&lt;br /&gt;
&lt;br /&gt;
But check it out! 3 3 4 3 2 3 4 is a MODMOS of Porcupine[7]! Here's how we can get it by chromatically-altering Porcupine[7] one tone at a time:&lt;br /&gt;
&lt;br /&gt;
3 3 3 3 3 3 4&lt;br /&gt;
3 3 4 2 3 3 4&lt;br /&gt;
3 3 4 3 2 3 4&lt;br /&gt;
&lt;br /&gt;
And we see, not surprisingly, that this doesn't work the same way in 31edo.&lt;br /&gt;
&lt;br /&gt;
Start with a MODMOS of Orwell[9]: 4 4 3 3 4 3 4 3 3&lt;br /&gt;
Combine small steps: 4 4 6 4 3 4 6&lt;br /&gt;
&lt;br /&gt;
4 4 4 4 4 4 7 is as close as we can get to Porcupine[7], and it sure ain't the same. Our chroma (L-s) is 3\31, really different!&lt;br /&gt;
4 4 7 1 4 4 7&lt;br /&gt;
4 4 7 1 4 1 7&lt;br /&gt;
&lt;br /&gt;
Not even close!&lt;/body&gt;&lt;/html&gt;</pre></div>