896/891: Difference between revisions

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**Imported revision 370886248 - Original comment: **
14/11 and 13/11
 
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<h2>IMPORTED REVISION FROM WIKISPACES</h2>
{{Infobox Interval
This is an imported revision from Wikispaces. The revision metadata is included below for reference:<br>
| Ratio = 896/891
: This revision was by author [[User:jdfreivald|jdfreivald]] and made on <tt>2012-10-07 12:28:09 UTC</tt>.<br>
| Name = pentacircle comma, undecimal semicomma
: The original revision id was <tt>370886248</tt>.<br>
| Color name = s1uz2, Saluzo comma
: The revision comment was: <tt></tt><br>
| Comma = yes
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">The Pentacircle Comma, 896/891, is similar to the Didymus or syntonic comma, 81/80, in that it makes a stack of four fifths equal a major third (octave equivalent). In the case of 81/80, however, the major third is 5/4, while with the Pentacircle comma, the major third is 14/11.


Pentacircle can be factored into two superparticular commas, 364/363 and 352/351. 364/363 is the difference between (14/11 * 13/11) and 3/2. Tempering out this comma ensures that a major third and a minor third together add up to a perfect fifth; this isn't necessary for traditional minor and major thirds, because 5/4 * 6/5 = 3/2.
The '''pentacircle comma''' or '''undecimal semicomma''', '''896/891''' (9.68796 [[cent]]s), is an [[11-limit]] [[comma]] with monzo {{monzo|7 -4 0 1 -1}}. It is similar to the Didymus or syntonic comma, [[81/80]], in that it makes a stack of four fifths equal a major third (octave equivalent). In the case of 81/80, however, the major third is [[5/4]], while with the pentacircle comma, the major third is [[14/11]]. Tempering it out also equates [[33/32]] and [[28/27]].


[[Cantonpenta]] is an example of a scale that tempers out the pentacircle comma. Also, the MOSes with an octave period and 17\29 as a generator temper out the pentacircle comma. Finally, see the article on [[Pentacircle Chords]].</pre></div>
The pentacircle comma can be factored into two [[13-limit]] [[superparticular]] commas, [[364/363]] (which is {{monzo| 2 -1 0 1 -2 1 }}) and [[352/351]] (which is {{monzo| 5 -3 0 0 1 -1 }}).
<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;pentacircle comma&lt;/title&gt;&lt;/head&gt;&lt;body&gt;The Pentacircle Comma, 896/891, is similar to the Didymus or syntonic comma, 81/80, in that it makes a stack of four fifths equal a major third (octave equivalent). In the case of 81/80, however, the major third is 5/4, while with the Pentacircle comma, the major third is 14/11.&lt;br /&gt;
364/363 is the minor minthma or gentle comma, which is the difference between a stack of 14/11 and [[13/11]] ([[182/121]]) and [[3/2]]. If 364/363 is tempered out, a 14/11 major third and a 13/11 minor third become [[fifth complement]]s; that is, they add up to a perfect fifth. (This isn't necessary for traditional minor and major thirds, because 5/4 × 6/5 = 3/2.)
&lt;br /&gt;
 
Pentacircle can be factored into two superparticular commas, 364/363 and 352/351. 364/363 is the difference between (14/11 * 13/11) and 3/2. Tempering out this comma ensures that a major third and a minor third together add up to a perfect fifth; this isn't necessary for traditional minor and major thirds, because 5/4 * 6/5 = 3/2.&lt;br /&gt;
352/351 is the major minthma. Tempering it out means 13/11 is equated with the pythagorean minor third, [[32/27]]. Tempering out 352/351 also makes [[11/9]] and [[16/13]] fifth complements of each other.
&lt;br /&gt;
 
&lt;a class="wiki_link" href="/Cantonpenta"&gt;Cantonpenta&lt;/a&gt; is an example of a scale that tempers out the pentacircle comma. Also, the MOSes with an octave period and 17\29 as a generator temper out the pentacircle comma. Finally, see the article on &lt;a class="wiki_link" href="/Pentacircle%20Chords"&gt;Pentacircle Chords&lt;/a&gt;.&lt;/body&gt;&lt;/html&gt;</pre></div>
Each of these commas has their own essentially tempered chords; see the articles on [[pentacircle chords]], [[minor minthmic chords]], and [[major minthmic chords]].
 
== Sagittal notation ==
In the [[Sagittal]] system, the downward version of this comma (possibly tempered) is represented by the sagittal {{sagittal | )!( }} and is called the '''11/7 kleisma''', or '''11/7k''' for short, because the simplest interval it notates is 11/7, as for example in A-F{{nbhsp}}{{sagittal | )!( }}. The upward version is called '''7/11k''' or '''11/7k up''' and is represented by {{sagittal| )|( }}.
 
== Temperaments ==
Tempering out 896/891 in the 11-limit leads to the [[rank-4]] [[pentacircle]] temperament. This temperament naturally extends to the 13-limit via 352/351 and 364/363. Tridecimal pentacircle is supported by the following edos, using their patent vals: {{EDOs|17, 22, 24, 29, 41, 46, 58, 63, 65, 80, 87, 92, 104, 109, 121}}, etc. The [[2.3.7.11.13 subgroup|2.3.7.11.13-]][[subgroup]] version of this temperament is known as [[parapyth]], and the 2.3.11/7.13/7-subgroup version of it is known as [[pepperoni]].
 
== See also ==
* [[Pentacircle clan]], the clan of rank-3 temperaments where it is tempered out
* [[Small comma]]
* [[Cantonpenta]], a scale that tempers out the pentacircle comma
 
[[Category:Pentacircle]]
[[Category:Commas named for their regular temperament properties]]

Latest revision as of 17:40, 5 March 2026

Interval information
Ratio 896/891
Factorization 27 × 3-4 × 7 × 11-1
Monzo [7 -4 0 1 -1
Size in cents 9.687961¢
Names pentacircle comma,
undecimal semicomma
Color name s1uz2, Saluzo comma
FJS name [math]\displaystyle{ \text{m2}^{7}_{11} }[/math]
Special properties reduced
Tenney norm (log2 nd) 19.6066
Weil norm (log2 max(n, d)) 19.6147
Wilson norm (sopfr(nd)) 44
Comma size small
Open this interval in xen-calc

The pentacircle comma or undecimal semicomma, 896/891 (9.68796 cents), is an 11-limit comma with monzo [7 -4 0 1 -1. It is similar to the Didymus or syntonic comma, 81/80, in that it makes a stack of four fifths equal a major third (octave equivalent). In the case of 81/80, however, the major third is 5/4, while with the pentacircle comma, the major third is 14/11. Tempering it out also equates 33/32 and 28/27.

The pentacircle comma can be factored into two 13-limit superparticular commas, 364/363 (which is [2 -1 0 1 -2 1) and 352/351 (which is [5 -3 0 0 1 -1).

364/363 is the minor minthma or gentle comma, which is the difference between a stack of 14/11 and 13/11 (182/121) and 3/2. If 364/363 is tempered out, a 14/11 major third and a 13/11 minor third become fifth complements; that is, they add up to a perfect fifth. (This isn't necessary for traditional minor and major thirds, because 5/4 × 6/5 = 3/2.)

352/351 is the major minthma. Tempering it out means 13/11 is equated with the pythagorean minor third, 32/27. Tempering out 352/351 also makes 11/9 and 16/13 fifth complements of each other.

Each of these commas has their own essentially tempered chords; see the articles on pentacircle chords, minor minthmic chords, and major minthmic chords.

Sagittal notation

In the Sagittal system, the downward version of this comma (possibly tempered) is represented by the sagittal and is called the 11/7 kleisma, or 11/7k for short, because the simplest interval it notates is 11/7, as for example in A-F⁠ ⁠. The upward version is called 7/11k or 11/7k up and is represented by .

Temperaments

Tempering out 896/891 in the 11-limit leads to the rank-4 pentacircle temperament. This temperament naturally extends to the 13-limit via 352/351 and 364/363. Tridecimal pentacircle is supported by the following edos, using their patent vals: 17, 22, 24, 29, 41, 46, 58, 63, 65, 80, 87, 92, 104, 109, 121, etc. The 2.3.7.11.13-subgroup version of this temperament is known as parapyth, and the 2.3.11/7.13/7-subgroup version of it is known as pepperoni.

See also