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<h2>IMPORTED REVISION FROM WIKISPACES</h2>
#REDIRECT [[Pergen]]
This is an imported revision from Wikispaces. The revision metadata is included below for reference:<br>
: This revision was by author [[User:TallKite|TallKite]] and made on <tt>2017-11-18 02:01:59 UTC</tt>.<br>
: The original revision id was <tt>621910225</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>
<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">**Pergen** (pronounced "peer-gen") names are a way of identifying rank-2 and rank-3 regular temperaments by their periods and generators. They are somewhat JI-agnostic in that they don't use higher primes. Rank-2 names only refer to the first two primes in the prime subgroup, and rank-3 names only refer to the first three primes.


If a rank-2 temperament uses the primes 2 and 3 in its comma(s), then the period can be expressed as the octave 2/1, or some fraction of an octave. The generator can be expressed as a 3-limit interval, or some fraction of one. The fraction is always of the form 1/N, in other words, the octave or the 3-limit interval is **split** into N parts. A 3-limit interval which is split into multiple generators is called a **multi-gen**.
See [[Pergen]].
 
For example,the srutal temperament splits the octave in two, and its pergen name is half-octave. The name is written {P8/2, P5}. Curly brackets are used because the name is a set of intervals. The dicot temperament splits the fifth in two, and is called half-fifth, written {P8, P5/2}. Porcupine is third-fourth, etc. Semaphore, which means "semi-fourth", is already sort of a pergen name.
 
In a sense, pergen names are categories, because many temperaments will have the same pergen name. This has the advantage of reducing the hundreds (thousands?) of temperament names to perhaps a few dozen categories. It also focuses on the melodic properties of the temperament.
 
The largest category contains all commas of the form 2&lt;span style="vertical-align: super;"&gt;x &lt;/span&gt;3&lt;span style="vertical-align: super;"&gt;y &lt;/span&gt;P or 2&lt;span style="vertical-align: super;"&gt;x &lt;/span&gt;3&lt;span style="vertical-align: super;"&gt;y &lt;/span&gt;P&lt;span style="vertical-align: super;"&gt;-1&lt;/span&gt;, where P is a prime (e.g. 81/80 or 64/63). The period is the octave, and the generator is the fifth. Such temperaments are called fifth-based. The 4th is also a generator, and in fact every temperament has at least one alternate generator. To avoid ambiguity, the generator and the multi-gen are chosen to minimize the amount of splitting of the multi-gen, and as a tie-breaker, to minimize the size in cents of the multi-gen. There is only one exception to this rule: the fifth is preferred over the fourth, to follow historical precedent.
 
For example, srutal could be {P8/2, M2/2}, but P5 is preferred because it is unsplit. Or it could be {P8/2, P12}, but P5 is preferred because it is smaller. Or it could be {P8/2, P4}, but P5 is always preferred over P4. Note that P5/2 is __not__ preferred over P4/2. For example, decimal is {P8/2, P4/2}, not {P8/2, P5/2}.
 
||||~ pergen name ||||||||~ examples ||
||~ written ||~ spoken ||~ comma(s) ||~ name ||||~ color name ||
||= {P8, P5} ||= fifth-based ||= 81/80 ||= meantone ||= green ||= gT ||
||= " ||= " ||= 64/63 ||= archy ||= red ||= rT ||
||= " ||= " ||= (-14,8,0,0,1) ||= schismic ||= large yellow ||= LyT ||
||= " ||= " ||= 81/80 &amp; 126/125 ||= septimal meantone ||= green and bluish-blue ||= g&amp;bg&lt;span style="vertical-align: super;"&gt;3&lt;/span&gt;T ||
||= {P8/2, P5} ||= half-octave ||= (11, -4, -2) ||= srutal ||= small deep green ||= sggT ||
||= " ||= " ||= 81/80 &amp; 50/49 ||= injera ||= deep reddish and green ||= rryy&amp;gT ||
||= {P8, P5/2} ||= half-fifth ||= 25/24 ||= dicot ||= deep yellow ||= yyT ||
||= " ||= " ||= (-1,5,0,0,-2) ||= mohajira ||= deep amber ||= aaT ||
||= {P8, P4/2} ||= half-fourth ||= 49/48 ||= semaphore ||= deep blue ||= bbT ||
||= {P8, P4/3} ||= third-fourth ||= 250/243 ||= porcupine ||= triple yellow ||= y&lt;span style="vertical-align: super;"&gt;3&lt;/span&gt;T ||
||= {P8, P11/3} ||= third-eleventh ||= (12,-1,0,0,-3) ||= small triple amber ||= small triple amber ||= sa&lt;span style="vertical-align: super;"&gt;3&lt;/span&gt;T ||
||= {P8/2, P4/2} ||= half-octave, half-fourth ||= 25/24 &amp; 49/48 ||= decimal ||= deep yellow and deep blue ||= yy&amp;bbT ||
||= {P8/4, P5} ||= quarter-octave ||= (3,4,-4) ||= diminished ||= quadruple green ||= g&lt;span style="vertical-align: super;"&gt;4&lt;/span&gt;T ||
For the 2.3... prime subgroup, the color names indicate the amount of splitting: deep splits something into two parts, triple into three parts, etc.
 
For quadruple colors, the 3-limit multi-gen may be the major 2nd 9/8. For hextuple, it may be the minor 3rd 32/27. These intervals may also be voiced wider, as 3/1, 9/4, etc. To avoid cumbersome degree names like 16th or 18th, for degrees above 11, the widening is indicated with a "W". Thus 3/1 = WP5, 9/2 = WWM2, etc. Thus magic is {P8, WP5/5} = fifth-wide-fifth.
 
For non-standard prime groups, the period uses the first prime only, and the multi-gen uses the first two primes only. [[Kite's color notation|Color notation ]]is used to indicate primes higher than 3. For example, 2.5.7 with 50/49 tempered out is {P8/2, y3} = half-octave, yellow-third.
 
Rank-3 pergen names have three intervals, any of which may be split. The unsplit 2.3.5... subgroup is {P8, P5, y3} = fifth-and-third-based. 2.3.5.7 with 50/49 tempered out is {P8/2, P5, y3}.
 
Rank-4 temperaments can be named similarly. Rank-1 temperaments could have pergen names, such as {P8/12} for 12-edo or {P12/13} for 13-ed3, but there's no particular reason to do so.</pre></div>
<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;pergen names&lt;/title&gt;&lt;/head&gt;&lt;body&gt;&lt;strong&gt;Pergen&lt;/strong&gt; (pronounced &amp;quot;peer-gen&amp;quot;) names are a way of identifying rank-2 and rank-3 regular temperaments by their periods and generators. They are somewhat JI-agnostic in that they don't use higher primes. Rank-2 names only refer to the first two primes in the prime subgroup, and rank-3 names only refer to the first three primes.&lt;br /&gt;
&lt;br /&gt;
If a rank-2 temperament uses the primes 2 and 3 in its comma(s), then the period can be expressed as the octave 2/1, or some fraction of an octave. The generator can be expressed as a 3-limit interval, or some fraction of one. The fraction is always of the form 1/N, in other words, the octave or the 3-limit interval is &lt;strong&gt;split&lt;/strong&gt; into N parts. A 3-limit interval which is split into multiple generators is called a &lt;strong&gt;multi-gen&lt;/strong&gt;.&lt;br /&gt;
&lt;br /&gt;
For example,the srutal temperament splits the octave in two, and its pergen name is half-octave. The name is written {P8/2, P5}. Curly brackets are used because the name is a set of intervals. The dicot temperament splits the fifth in two, and is called half-fifth, written {P8, P5/2}. Porcupine is third-fourth, etc. Semaphore, which means &amp;quot;semi-fourth&amp;quot;, is already sort of a pergen name. &lt;br /&gt;
&lt;br /&gt;
In a sense, pergen names are categories, because many temperaments will have the same pergen name. This has the advantage of reducing the hundreds (thousands?) of temperament names to perhaps a few dozen categories. It also focuses on the melodic properties of the temperament.&lt;br /&gt;
&lt;br /&gt;
The largest category contains all commas of the form 2&lt;span style="vertical-align: super;"&gt;x &lt;/span&gt;3&lt;span style="vertical-align: super;"&gt;y &lt;/span&gt;P or 2&lt;span style="vertical-align: super;"&gt;x &lt;/span&gt;3&lt;span style="vertical-align: super;"&gt;y &lt;/span&gt;P&lt;span style="vertical-align: super;"&gt;-1&lt;/span&gt;, where P is a prime (e.g. 81/80 or 64/63). The period is the octave, and the generator is the fifth. Such temperaments are called fifth-based. The 4th is also a generator, and in fact every temperament has at least one alternate generator. To avoid ambiguity, the generator and the multi-gen are chosen to minimize the amount of splitting of the multi-gen, and as a tie-breaker, to minimize the size in cents of the multi-gen. There is only one exception to this rule: the fifth is preferred over the fourth, to follow historical precedent. &lt;br /&gt;
&lt;br /&gt;
For example, srutal could be {P8/2, M2/2}, but P5 is preferred because it is unsplit. Or it could be {P8/2, P12}, but P5 is preferred because it is smaller. Or it could be {P8/2, P4}, but P5 is always preferred over P4. Note that P5/2 is &lt;u&gt;not&lt;/u&gt; preferred over P4/2. For example, decimal is {P8/2, P4/2}, not {P8/2, P5/2}.&lt;br /&gt;
&lt;br /&gt;
 
 
&lt;table class="wiki_table"&gt;
    &lt;tr&gt;
        &lt;th colspan="2"&gt;pergen name&lt;br /&gt;
&lt;/th&gt;
        &lt;th colspan="4"&gt;examples&lt;br /&gt;
&lt;/th&gt;
    &lt;/tr&gt;
    &lt;tr&gt;
        &lt;th&gt;written&lt;br /&gt;
&lt;/th&gt;
        &lt;th&gt;spoken&lt;br /&gt;
&lt;/th&gt;
        &lt;th&gt;comma(s)&lt;br /&gt;
&lt;/th&gt;
        &lt;th&gt;name&lt;br /&gt;
&lt;/th&gt;
        &lt;th colspan="2"&gt;color name&lt;br /&gt;
&lt;/th&gt;
    &lt;/tr&gt;
    &lt;tr&gt;
        &lt;td style="text-align: center;"&gt;{P8, P5}&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;fifth-based&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;81/80&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;meantone&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;green&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;gT&lt;br /&gt;
&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr&gt;
        &lt;td style="text-align: center;"&gt;&amp;quot;&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;&amp;quot;&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;64/63&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;archy&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;red&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;rT&lt;br /&gt;
&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr&gt;
        &lt;td style="text-align: center;"&gt;&amp;quot;&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;&amp;quot;&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;(-14,8,0,0,1)&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;schismic&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;large yellow&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;LyT&lt;br /&gt;
&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr&gt;
        &lt;td style="text-align: center;"&gt;&amp;quot;&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;&amp;quot;&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;81/80 &amp;amp; 126/125&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;septimal meantone&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;green and bluish-blue&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;g&amp;amp;bg&lt;span style="vertical-align: super;"&gt;3&lt;/span&gt;T&lt;br /&gt;
&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr&gt;
        &lt;td style="text-align: center;"&gt;{P8/2, P5}&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;half-octave&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;(11, -4, -2)&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;srutal&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;small deep green&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;sggT&lt;br /&gt;
&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr&gt;
        &lt;td style="text-align: center;"&gt;&amp;quot;&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;&amp;quot;&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;81/80 &amp;amp; 50/49&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;injera&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;deep reddish and green&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;rryy&amp;amp;gT&lt;br /&gt;
&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr&gt;
        &lt;td style="text-align: center;"&gt;{P8, P5/2}&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;half-fifth&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;25/24&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;dicot&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;deep yellow&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;yyT&lt;br /&gt;
&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr&gt;
        &lt;td style="text-align: center;"&gt;&amp;quot;&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;&amp;quot;&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;(-1,5,0,0,-2)&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;mohajira&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;deep amber&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;aaT&lt;br /&gt;
&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr&gt;
        &lt;td style="text-align: center;"&gt;{P8, P4/2}&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;half-fourth&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;49/48&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;semaphore&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;deep blue&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;bbT&lt;br /&gt;
&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr&gt;
        &lt;td style="text-align: center;"&gt;{P8, P4/3}&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;third-fourth&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;250/243&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;porcupine&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;triple yellow&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;y&lt;span style="vertical-align: super;"&gt;3&lt;/span&gt;T&lt;br /&gt;
&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr&gt;
        &lt;td style="text-align: center;"&gt;{P8, P11/3}&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;third-eleventh&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;(12,-1,0,0,-3)&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;small triple amber&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;small triple amber&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;sa&lt;span style="vertical-align: super;"&gt;3&lt;/span&gt;T&lt;br /&gt;
&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr&gt;
        &lt;td style="text-align: center;"&gt;{P8/2, P4/2}&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;half-octave, half-fourth&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;25/24 &amp;amp; 49/48&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;decimal&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;deep yellow and deep blue&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;yy&amp;amp;bbT&lt;br /&gt;
&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr&gt;
        &lt;td style="text-align: center;"&gt;{P8/4, P5}&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;quarter-octave&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;(3,4,-4)&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;diminished&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;quadruple green&lt;br /&gt;
&lt;/td&gt;
        &lt;td style="text-align: center;"&gt;g&lt;span style="vertical-align: super;"&gt;4&lt;/span&gt;T&lt;br /&gt;
&lt;/td&gt;
    &lt;/tr&gt;
&lt;/table&gt;
 
For the 2.3... prime subgroup, the color names indicate the amount of splitting: deep splits something into two parts, triple into three parts, etc.&lt;br /&gt;
&lt;br /&gt;
For quadruple colors, the 3-limit multi-gen may be the major 2nd 9/8. For hextuple, it may be the minor 3rd 32/27. These intervals may also be voiced wider, as 3/1, 9/4, etc. To avoid cumbersome degree names like 16th or 18th, for degrees above 11, the widening is indicated with a &amp;quot;W&amp;quot;. Thus 3/1 = WP5, 9/2 = WWM2, etc. Thus magic is {P8, WP5/5} = fifth-wide-fifth.&lt;br /&gt;
&lt;br /&gt;
For non-standard prime groups, the period uses the first prime only, and the multi-gen uses the first two primes only. &lt;a class="wiki_link" href="/Kite%27s%20color%20notation"&gt;Color notation &lt;/a&gt;is used to indicate primes higher than 3. For example, 2.5.7 with 50/49 tempered out is {P8/2, y3} = half-octave, yellow-third.&lt;br /&gt;
&lt;br /&gt;
Rank-3 pergen names have three intervals, any of which may be split. The unsplit 2.3.5... subgroup is {P8, P5, y3} = fifth-and-third-based. 2.3.5.7 with 50/49 tempered out is {P8/2, P5, y3}.&lt;br /&gt;
&lt;br /&gt;
Rank-4 temperaments can be named similarly. Rank-1 temperaments could have pergen names, such as {P8/12} for 12-edo or {P12/13} for 13-ed3, but there's no particular reason to do so.&lt;/body&gt;&lt;/html&gt;</pre></div>

Latest revision as of 14:49, 21 September 2018

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See Pergen.