34/21: Difference between revisions

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**Imported revision 602876782 - Original comment: **
 
Clarify golden ratio
 
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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>
| Name = septendecimal supraminor sixth
: This revision was by author [[User:xenwolf|xenwolf]] and made on <tt>2016-12-28 14:08:06 UTC</tt>.<br>
| Color name = 17or6, soru 6th
: The original revision id was <tt>602876782</tt>.<br>
| Sound = ji-34-21-csound-foscil-220hz.mp3
: 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">**34/21**
| 1 -1 0 -1 0 0 1&gt;
834.1745 cents
[[media type="file" key="ji-34-21-csound-foscil-220hz.mp3"]] [[file:xenharmonic/ji-34-21-csound-foscil-220hz.mp3|sound sample]]


The **septendecimal supraminor sixth**. Its inverse is the septendecimal submajor third [[21_17|21/17]].
'''34/21''' is the '''septendecimal supraminor sixth'''.


See [[Gallery of Just Intervals]]</pre></div>
This interval is a ratio of two consecutive Fibonacci numbers, therefore it approximates the [[Acoustic phi|acoustic golden ratio]]. In this case, 34/21 is ~1.1 [[cent|¢]] sharp of the golden ratio. Two fall short of [[21/8]] and three of them fall short of [[17/4]] by [[9261/9248]], which becomes particularly significant in [[Sephiroth]] temperament.
<h4>Original HTML content:</h4>
== Approximation ==
<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;34_21&lt;/title&gt;&lt;/head&gt;&lt;body&gt;&lt;strong&gt;34/21&lt;/strong&gt;&lt;br /&gt;
{{Interval edo approximation|21/17}}
| 1 -1 0 -1 0 0 1&amp;gt;&lt;br /&gt;
== See also ==
834.1745 cents&lt;br /&gt;
* [[21/17]] – its [[octave complement]]
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* [[Gallery of just intervals]]
&lt;br /&gt;
 
The &lt;strong&gt;septendecimal supraminor sixth&lt;/strong&gt;. Its inverse is the septendecimal submajor third &lt;a class="wiki_link" href="/21_17"&gt;21/17&lt;/a&gt;.&lt;br /&gt;
[[Category:Sixth]]
&lt;br /&gt;
[[Category:Supraminor sixth]]
See &lt;a class="wiki_link" href="/Gallery%20of%20Just%20Intervals"&gt;Gallery of Just Intervals&lt;/a&gt;&lt;/body&gt;&lt;/html&gt;</pre></div>
[[Category:Golden ratio approximations]]
{{todo|expand}}

Latest revision as of 19:33, 27 August 2026

Interval information
Ratio 34/21
Factorization 2 × 3-1 × 7-1 × 17
Monzo [1 -1 0 -1 0 0 1
Size in cents 834.1745 ¢
Name septendecimal supraminor sixth
Color name 17or6, soru 6th
FJS name [math]\displaystyle{ \text{m6}^{17}_{7} }[/math]
Special properties reduced
Tenney norm (log2 nd) 9.47978
Weil norm (log2 max(n, d)) 10.1749
Wilson norm (sopfr(nd)) 29

[sound info]
Open this interval in xen-calc

34/21 is the septendecimal supraminor sixth.

This interval is a ratio of two consecutive Fibonacci numbers, therefore it approximates the acoustic golden ratio. In this case, 34/21 is ~1.1 ¢ sharp of the golden ratio. Two fall short of 21/8 and three of them fall short of 17/4 by 9261/9248, which becomes particularly significant in Sephiroth temperament.

Approximation

Edo approximations for 34/21 (834.17 ¢)
≤ 80edo, relative error ≤ 10%
Edo Step size Cents (¢) Absolute error (¢) Relative error (%)
3 2\3 800.00 -34.17 -8.54
10 7\10 840.00 +5.83 +4.85
13 9\13 830.77 -3.41 -3.69
20 14\20 840.00 +5.83 +9.71
23 16\23 834.78 +0.61 +1.17
26 18\26 830.77 -3.41 -7.38
33 23\33 836.36 +2.19 +6.02
36 25\36 833.33 -0.84 -2.52
46 32\46 834.78 +0.61 +2.33
49 34\49 832.65 -1.52 -6.21
56 39\56 835.71 +1.54 +7.19
59 41\59 833.90 -0.28 -1.36
62 43\62 832.26 -1.92 -9.90
69 48\69 834.78 +0.61 +3.50
72 50\72 833.33 -0.84 -5.05
79 55\79 835.44 +1.27 +8.35

See also