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<h2>IMPORTED REVISION FROM WIKISPACES</h2>
{{Infobox ET}}
This is an imported revision from Wikispaces. The revision metadata is included below for reference:<br>
{{ED intro}}
: This revision was by author [[User:xenwolf|xenwolf]] and made on <tt>2012-03-30 04:12:40 UTC</tt>.<br>
: The original revision id was <tt>316091620</tt>.<br>
: The revision comment was: <tt>"here" links are poor from a psychological POV</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">The //612 equal division// divides the octave into 612 equal parts of 1.961 cents each. It is a very strong [[5-limit]] system, a fact noted by Bosanquet and Barbour. It tempers out the sasktel comma, |485 -306&gt;, in the 3-limit and in the 5-limit |-52 -17 34&gt;, the septendecima, |1 -27 18&gt;, the ennealimma, |-53 10 16&gt;, the kwazy comma, |54 -37 2&gt;, the monzisma, |-107 47 14&gt;, the fortune comma, and |161 -84 -12&gt;, the atom. In the 7-limit it tempers out 2401/2400 and 4375/4374, so that it supports [[Ragismic microtemperaments#Ennealimmal|ennealimmal temperament]], and in fact provides the [[optimal patent val]] for ennealimmal. The 7-limit val for 612 can be characterized as the ennealimmal commas plus the kwasy comma. In the 11-limit, it tempers out 3025/3024 and 9801/9800, so that 612 supports [[Ragismic microtemperaments#Ennealimmal|hemiennealimmal temperament]].


The 612 division has been proposed as a logarithmic [[interval size measure]]; since one step is nearly the same size as the schisma, (32805/32768) it's been called the skisma, notated sk. Since 612 is divisible by 2, 3, 4, 6, 9, 12, 17, 18, 34, 36, 51, 68, 102, 153, 204 and 306, it can readily express the step sizes of the 12, 17, 34, 68 and 72 divisions. A table of intervals approximated by 612 can be found under [[Table of 612edo intervals]].</pre></div>
== Theory ==
<h4>Original HTML content:</h4>
612edo is a very strong [[5-limit]] system, a fact noted by {{w|Isaac Newton}}<ref>[https://emusicology.org/index.php/EMR/article/view/7647/6030 Muzzulini, Daniel. 2021. "Isaac Newton's Microtonal Approach to Just Intonation". ''Empirical Musicology Review'' 15 (3-4):223-48. https://doi.org/10.18061/emr.v15i3-4.7647.]</ref>, {{w|Robert Holford Macdowall Bosanquet|R. H. M. Bosanquet}}{{citation needed}} and {{w|James Murray Barbour}}{{citation needed}}. As an equal temperament, it [[tempering out|tempers out]] the {{monzo| 485 -306 }} ([[sasktel comma]]) in the 3-limit, and in the 5-limit {{monzo| 1 -27 18 }} ([[ennealimma]]), {{monzo| -52 -17 34 }} ([[septendecima]]), {{monzo| -53 10 16 }} ([[kwazy comma]]), {{monzo| 54 -37 2 }} ([[monzisma]]), {{monzo| -107 47 14 }} (fortune comma), and {{monzo| 161 -84 -12 }} ([[atom]]). In the 7-limit it tempers out [[2401/2400]] and [[4375/4374]], so that it [[support]]s the [[ennealimmal]] temperament, and in fact provides the [[optimal patent val]] for ennealimmal. The 7-limit val for 612 can be characterized as the ennealimmal commas plus the kwazy comma. In the 11-limit, it tempers out [[3025/3024]] and [[9801/9800]], so that 612 supports the [[hemiennealimmal]] temperament. In the 13-limit, it tempers [[2200/2197]] and [[4096/4095]].
<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;612edo&lt;/title&gt;&lt;/head&gt;&lt;body&gt;The &lt;em&gt;612 equal division&lt;/em&gt; divides the octave into 612 equal parts of 1.961 cents each. It is a very strong &lt;a class="wiki_link" href="/5-limit"&gt;5-limit&lt;/a&gt; system, a fact noted by Bosanquet and Barbour. It tempers out the sasktel comma, |485 -306&amp;gt;, in the 3-limit and in the 5-limit |-52 -17 34&amp;gt;, the septendecima, |1 -27 18&amp;gt;, the ennealimma, |-53 10 16&amp;gt;, the kwazy comma, |54 -37 2&amp;gt;, the monzisma, |-107 47 14&amp;gt;, the fortune comma, and |161 -84 -12&amp;gt;, the atom. In the 7-limit it tempers out 2401/2400 and 4375/4374, so that it supports &lt;a class="wiki_link" href="/Ragismic%20microtemperaments#Ennealimmal"&gt;ennealimmal temperament&lt;/a&gt;, and in fact provides the &lt;a class="wiki_link" href="/optimal%20patent%20val"&gt;optimal patent val&lt;/a&gt; for ennealimmal. The 7-limit val for 612 can be characterized as the ennealimmal commas plus the kwasy comma. In the 11-limit, it tempers out 3025/3024 and 9801/9800, so that 612 supports &lt;a class="wiki_link" href="/Ragismic%20microtemperaments#Ennealimmal"&gt;hemiennealimmal temperament&lt;/a&gt;.&lt;br /&gt;
 
&lt;br /&gt;
The 612edo step has been proposed as the logarithmic [[interval size measure]] '''skisma''' (or '''sk'''), since one step is nearly the same size as the [[schisma]] (32805/32768), 1/12 of a [[Pythagorean comma]] or 1/11 of a [[syntonic comma]]. Since 612 is divisible by {{EDOs| 2, 3, 4, 6, 9, 12, 17, 18, 34, 36, 51, 68, 102, 153, 204 and 306 }}, it can readily express the step sizes of the 12, 17, 34, and 68 divisions. A table of intervals approximated by 612 can be found under [[Table of 612edo intervals]].
The 612 division has been proposed as a logarithmic &lt;a class="wiki_link" href="/interval%20size%20measure"&gt;interval size measure&lt;/a&gt;; since one step is nearly the same size as the schisma, (32805/32768) it's been called the skisma, notated sk. Since 612 is divisible by 2, 3, 4, 6, 9, 12, 17, 18, 34, 36, 51, 68, 102, 153, 204 and 306, it can readily express the step sizes of the 12, 17, 34, 68 and 72 divisions. A table of intervals approximated by 612 can be found under &lt;a class="wiki_link" href="/Table%20of%20612edo%20intervals"&gt;Table of 612edo intervals&lt;/a&gt;.&lt;/body&gt;&lt;/html&gt;</pre></div>
 
=== Prime harmonics ===
{{Harmonics in equal|612}}
 
== Regular temperament properties ==
{| class="wikitable center-4 center-5 center-6"
|-
! rowspan="2" | [[Subgroup]]
! rowspan="2" | [[Comma list]]
! rowspan="2" | [[Mapping]]
! rowspan="2" | Optimal<br>8ve stretch (¢)
! colspan="2" | Tuning error
|-
! [[TE error|Absolute]] (¢)
! [[TE simple badness|Relative]] (%)
|-
| 2.3.5
| {{monzo| 1 -27 18 }}, {{monzo| -53 10 16 }}
| {{Mapping| 612 970 1421 }}
| +0.0044
| 0.0089
| 0.46
|-
| 2.3.5.7
| 2401/2400, 4375/4374, {{monzo| -53 10 16 }}
| {{Mapping| 612 970 1421 1718 }}
| +0.0210
| 0.0297
| 1.52
|-
| 2.3.5.7.11
| 2401/2400, 3025/3024, 4375/4374, {{monzo| 21 -6 -7 -2 3 }}
| {{Mapping| 612 970 1421 1718 2117 }}
| +0.0363
| 0.0406
| 2.07
|-
| 2.3.5.7.11.13
| 2200/2197, 2401/2400, 3025/3024, 4096/4095, 4375/4374
| {{Mapping| 612 970 1421 1718 2117 2265 }}
| +0.0010
| 0.0871
| 4.44
|-
| 2.3.5.7.11.13.19
| 1331/1330, 1540/1539, 2200/2197, 2376/2375, 2926/2925, 4096/4095
| {{Mapping| 612 970 1421 1718 2117 2265 2600 }}
| −0.0168
| 0.0917
| 4.68
|}
* 612et has a lower relative error than any previous equal temperaments in the 5-limit. Not until [[1171edo|1171]] do we find a better equal temperament in terms of either absolute error or relative error.
* It also has a lower absolute error in the 7- and 11-limit than any previous equal temperaments, and is only bettered by [[935edo|935]] and [[836edo|836]], respectively.
 
=== Rank-2 temperaments ===
{| class="wikitable center-all left-5"
|+ style="font-size: 105%;" | Table of rank-2 temperaments by generator
|-
! Periods<br>per 8ve
! Generator*
! Cents*
! Associated<br>ratio*
! Temperaments
|-
| 1
| 113\612
| 221.57
| 8388608/7381125
| [[Fortune]]
|-
| 1
| 127\612
| 249.02
| {{monzo| -26 18 -1 }}
| [[Monzismic]]
|-
| 2
| 83\612
| 162.75
| 1125/1024
| [[Crazy]]
|-
| 4
| 194\612<br>(41\612)
| 380.39<br>(80.39)
| 81/65<br>(22/21)
| [[Quasithird]]
|-
| 9
| 133\612<br>(25\612)
| 315.69<br>(49.02)
| 6/5<br>(36/35)
| [[Ennealimmal]]
|-
| 12
| 124\612<br>(22\612)
| 243.137<br>(43.14)
| 3145728/2734375<br>(?)
| [[Magnesium]]
|-
| 12
| 254\612<br>(1\612)
| 498.04<br>(1.96)
| 4/3<br>(32805/32768)
| [[Atomic]]
|-
| 17
| 127\612<br>(17\612)
| 249.02<br>(33.33)
| {{monzo| -23 5 9 -2 }}<br>(100352/98415)
| [[Chlorine]]
|-
| 18
| 127\612<br>(9\612)
| 249.02<br>(17.65)
| 231/200<br>(99/98)
| [[Hemiennealimmal]] (11-limit)
|}
<nowiki/>* [[Normal lists|Octave-reduced form]], reduced to the first half-octave, and [[normal lists|minimal form]] in parentheses if distinct
 
== Music ==
; [[Eliora]]
* [https://www.youtube.com/watch?v=_DrkrgkiaAY ''Theme and Variations in Hemiennealimmal''] (2023)
 
== Notes ==
<references />
 
[[Category:Ennealimmal]]
[[Category:Hemiennealimmal]]
[[Category:Listen]]
Retrieved from "https://en.xen.wiki/w/612edo"