Porcupine: Difference between revisions
Wikispaces>jdfreivald **Imported revision 615923439 - Original comment: ** |
Wikispaces>jdfreivald **Imported revision 615923479 - 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:jdfreivald|jdfreivald]] and made on <tt>2017-07-26 07: | : This revision was by author [[User:jdfreivald|jdfreivald]] and made on <tt>2017-07-26 07:40:17 UTC</tt>.<br> | ||
: The original revision id was <tt> | : The original revision id was <tt>615923479</tt>.<br> | ||
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The basic 5-limit harmonic structure of porcupine can be understood simply by noting that tempering out 250/243 makes (4/3)^2 equivalent to (6/5)^3. In perhaps more familiar musical terms, this means two "perfect fourths" equals three "minor thirds". As a consequence of this, 4/3 is divided into 3 equal parts, and 6/5 is divided into 2 of those same equal parts. This is obviously in stark contrast to [[12edo]], and to meantone, in which neither 4/3 nor 6/5 can be divided into any number of equal parts. The "equal tetrachord" formed by dividing 4/3 into 3 equal parts is a characteristic feature of many porcupine scales. | The basic 5-limit harmonic structure of porcupine can be understood simply by noting that tempering out 250/243 makes (4/3)^2 equivalent to (6/5)^3. In perhaps more familiar musical terms, this means two "perfect fourths" equals three "minor thirds". As a consequence of this, 4/3 is divided into 3 equal parts, and 6/5 is divided into 2 of those same equal parts. This is obviously in stark contrast to [[12edo]], and to meantone, in which neither 4/3 nor 6/5 can be divided into any number of equal parts. The "equal tetrachord" formed by dividing 4/3 into 3 equal parts is a characteristic feature of many porcupine scales. | ||
[[image:porcupine.png | [[image:porcupine.png]] | ||
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The basic 5-limit harmonic structure of porcupine can be understood simply by noting that tempering out 250/243 makes (4/3)^2 equivalent to (6/5)^3. In perhaps more familiar musical terms, this means two &quot;perfect fourths&quot; equals three &quot;minor thirds&quot;. As a consequence of this, 4/3 is divided into 3 equal parts, and 6/5 is divided into 2 of those same equal parts. This is obviously in stark contrast to <a class="wiki_link" href="/12edo">12edo</a>, and to meantone, in which neither 4/3 nor 6/5 can be divided into any number of equal parts. The &quot;equal tetrachord&quot; formed by dividing 4/3 into 3 equal parts is a characteristic feature of many porcupine scales.<br /> | The basic 5-limit harmonic structure of porcupine can be understood simply by noting that tempering out 250/243 makes (4/3)^2 equivalent to (6/5)^3. In perhaps more familiar musical terms, this means two &quot;perfect fourths&quot; equals three &quot;minor thirds&quot;. As a consequence of this, 4/3 is divided into 3 equal parts, and 6/5 is divided into 2 of those same equal parts. This is obviously in stark contrast to <a class="wiki_link" href="/12edo">12edo</a>, and to meantone, in which neither 4/3 nor 6/5 can be divided into any number of equal parts. The &quot;equal tetrachord&quot; formed by dividing 4/3 into 3 equal parts is a characteristic feature of many porcupine scales.<br /> | ||
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