Wikispaces>Andrew_Heathwaite |
|
| (17 intermediate revisions by 11 users not shown) |
| Line 1: |
Line 1: |
| <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 = tridecimal augmented fourth, low tritone |
| : This revision was by author [[User:Andrew_Heathwaite|Andrew_Heathwaite]] and made on <tt>2011-10-07 19:40:30 UTC</tt>.<br>
| | | Color name = 3u4, thu 4th |
| : The original revision id was <tt>262739538</tt>.<br>
| | | Sound = jid_18_13_pluck_adu_dr220.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">In [[13-limit]] [[Just Intonation]], 18/13 is a low tritone measuring about 563.4¢. It represents the interval between the 13th and 18th overtones of the [[overtone scales|harmonic series]]. The low tritone in [[17edo]] approximates 18/13 quite well, while 17edo's approximations of [[13_8|13/8]] and [[9_8|9/8]] are both a little sharp. The inversion of 18/13 is 13/9, a high tritone measuring about 536.6¢; the interval between these two tridecimal (13-based) tritones is 169/162, approximately 73.2¢.
| |
|
| |
|
| Other just tritones include [[7_5|7/5]], [[10_7|10/7]], [[45_32|45/32]], [[64_45|64/45]], [[24_17|24/17]], [[17_12|17/12]], [[23_16|23/16]], [[32_23|32/23]], and, of course, infinitely many more intervals.
| | In [[13-limit]] [[just intonation]], '''18/13''', the '''tridecimal augmented fourth''' is a '''low [[tritone]]''' measuring about 563.4¢. It represents the interval between the 13th and 18th harmonics of the [[overtone scales|harmonic series]]. |
|
| |
|
| See: [[Gallery of Just Intervals]]</pre></div>
| | The low tritone in [[17edo]] approximates 18/13 quite well, while 17edo's approximations of [[13/8]] and [[9/8]] are both a little sharp. The inversion of 18/13 is [[13/9]], a high tritone measuring about 636.6¢; the interval between these two tridecimal (13-based) tritones is [[169/162]], approximately 73.2¢. |
| <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"><html><head><title>18_13</title></head><body>In <a class="wiki_link" href="/13-limit">13-limit</a> <a class="wiki_link" href="/Just%20Intonation">Just Intonation</a>, 18/13 is a low tritone measuring about 563.4¢. It represents the interval between the 13th and 18th overtones of the <a class="wiki_link" href="/overtone%20scales">harmonic series</a>. The low tritone in <a class="wiki_link" href="/17edo">17edo</a> approximates 18/13 quite well, while 17edo's approximations of <a class="wiki_link" href="/13_8">13/8</a> and <a class="wiki_link" href="/9_8">9/8</a> are both a little sharp. The inversion of 18/13 is 13/9, a high tritone measuring about 536.6¢; the interval between these two tridecimal (13-based) tritones is 169/162, approximately 73.2¢.<br />
| | {{Interval edo approximation|18/13}} |
| <br />
| | == See also == |
| Other just tritones include <a class="wiki_link" href="/7_5">7/5</a>, <a class="wiki_link" href="/10_7">10/7</a>, <a class="wiki_link" href="/45_32">45/32</a>, <a class="wiki_link" href="/64_45">64/45</a>, <a class="wiki_link" href="/24_17">24/17</a>, <a class="wiki_link" href="/17_12">17/12</a>, <a class="wiki_link" href="/23_16">23/16</a>, <a class="wiki_link" href="/32_23">32/23</a>, and, of course, infinitely many more intervals.<br />
| | |
| <br />
| | * [[13/9]] – its [[octave complement]] |
| See: <a class="wiki_link" href="/Gallery%20of%20Just%20Intervals">Gallery of Just Intervals</a></body></html></pre></div>
| | * [[13/12]] – its [[fifth complement]] |
| | * [[Gallery of just intervals]] |
| | |
| | [[Category:Tritone]] |
In 13-limit just intonation, 18/13, the tridecimal augmented fourth is a low tritone measuring about 563.4¢. It represents the interval between the 13th and 18th harmonics of the harmonic series.
The low tritone in 17edo approximates 18/13 quite well, while 17edo's approximations of 13/8 and 9/8 are both a little sharp. The inversion of 18/13 is 13/9, a high tritone measuring about 636.6¢; the interval between these two tridecimal (13-based) tritones is 169/162, approximately 73.2¢.
Approximation
Edo approximations for 18/13 (563.38 ¢)
≤ 80edo, relative error ≤ 10%
| Edo |
Step size |
Cents (¢) |
Absolute error (¢) |
Relative error (%)
|
| 2 |
1\2 |
600.00 |
+36.62 |
+6.10
|
| 15 |
7\15 |
560.00 |
-3.38 |
-4.23
|
| 17 |
8\17 |
564.71 |
+1.32 |
+1.88
|
| 19 |
9\19 |
568.42 |
+5.04 |
+7.98
|
| 30 |
14\30 |
560.00 |
-3.38 |
-8.46
|
| 32 |
15\32 |
562.50 |
-0.88 |
-2.35
|
| 34 |
16\34 |
564.71 |
+1.32 |
+3.75
|
| 36 |
17\36 |
566.67 |
+3.28 |
+9.85
|
| 47 |
22\47 |
561.70 |
-1.68 |
-6.58
|
| 49 |
23\49 |
563.27 |
-0.12 |
-0.48
|
| 51 |
24\51 |
564.71 |
+1.32 |
+5.63
|
| 64 |
30\64 |
562.50 |
-0.88 |
-4.71
|
| 66 |
31\66 |
563.64 |
+0.25 |
+1.40
|
| 68 |
32\68 |
564.71 |
+1.32 |
+7.50
|
| 79 |
37\79 |
562.03 |
-1.36 |
-8.93
|
See also