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Various equal divisions of the octave have close approximations of acoustic phi, or <span><math>φ</math></span> | |||
Various equal divisions of the octave have close approximations of acoustic phi, or , ≈833.090296357¢. <span><math>φ</math></span>If the <span><math>m^{th}</math></span> step of <span><math>n</math><span>ed2 is a close approximation of <span><math>φ</math></span>, the <span><math>n^{th}</math></span> step of <span><math>m</math><span>ed<span><math>φ</math></span> will be a close approximation of 2. | |||
If the <span><math>m^{th}</math></span> step of <span><math>n</math><span>ed2 is a close approximation of <span><math>φ</math></span>, the <span><math>n^{th}</math></span> step of <span><math>m</math><span>ed<span><math>φ</math></span> will be a close approximation of 2. | |||
For example, the 7th step of 10ed2 is 840¢, and the 10th step of 7ed<span><math>φ</math></span> is ≈1190.128995¢. | For example, the 7th step of 10ed2 is 840¢, and the 10th step of 7ed<span><math>φ</math></span> is ≈1190.128995¢. | ||
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{| class="wikitable" | {| class="wikitable" | ||
|+ | |+ | ||
| | | rowspan="2" |'''scale step''' | ||
| colspan="4" |'''10ed2''' | | colspan="4" |'''10ed2''' | ||
| colspan="4" |'''7edφ or 10ed(<math>2^{\frac{10log_2{φ}}{7}} ≈ 1.988629015</math>)''' | | colspan="4" |'''7edφ or 10ed(<math>2^{\frac{10log_2{φ}}{7}} ≈ 1.988629015</math>)''' | ||
|- | |- | ||
|'''frequency multiplier (definition)''' | |'''frequency multiplier (definition)''' | ||
|'''10ed2 frequency multiplier (decimal)''' | |'''10ed2 frequency multiplier (decimal)''' | ||
Line 123: | Line 121: | ||
|1190.128995 | |1190.128995 | ||
|119.0128995 | |119.0128995 | ||
|} | |||
{| class="wikitable" | |||
|+ | |||
| rowspan="2" |'''scale step''' | |||
| colspan="4" |'''13ed2''' | |||
| colspan="4" |'''9edφ or 13ed(<math>2^{\frac{10log_2{φ}}{7}} ≈ 1.988629015</math>)<math>2^{\frac{10log_2{φ}}{7}} ≈ 1.988629015</math>''' | |||
|- | |||
|'''frequency multiplier (definition)''' | |||
|'''10ed2 frequency multiplier (decimal)''' | |||
|'''pitch (¢)''' | |||
|'''Δ (¢)''' | |||
|'''frequency multiplier (definition)''' | |||
|'''frequency multiplier (decimal)''' | |||
|'''pitch (¢)''' | |||
|'''Δ (¢)''' | |||
|- | |||
|'''1''' | |||
| | |||
|1.054766076 | |||
|92.30769231 | |||
|92.30769231 | |||
| | |||
|1.054923213 | |||
|92.56558848 | |||
|92.56558848 | |||
|- | |||
|'''2''' | |||
| | |||
|1.112531476 | |||
|184.6153846 | |||
|92.30769231 | |||
| | |||
|1.112862986 | |||
|185.131177 | |||
|92.56558848 | |||
|- | |||
|'''3''' | |||
| | |||
|1.17346046 | |||
|276.9230769 | |||
|92.30769231 | |||
| | |||
|1.173984997 | |||
|277.6967655 | |||
|92.56558848 | |||
|- | |||
|'''4''' | |||
| | |||
|1.237726285 | |||
|369.2307692 | |||
|92.30769231 | |||
| | |||
|1.238464025 | |||
|370.2623539 | |||
|92.56558848 | |||
|- | |||
|'''5''' | |||
| | |||
|1.305511698 | |||
|461.5384615 | |||
|92.30769231 | |||
| | |||
|1.306484449 | |||
|462.8279424 | |||
|92.56558848 | |||
|- | |||
|'''6''' | |||
| | |||
|1.377009451 | |||
|553.8461538 | |||
|92.30769231 | |||
| | |||
|1.378240772 | |||
|555.3935309 | |||
|92.56558848 | |||
|- | |||
|'''7''' | |||
| | |||
|1.452422856 | |||
|646.1538462 | |||
|92.30769231 | |||
| | |||
|1.453938184 | |||
|647.9591194 | |||
|92.56558848 | |||
|- | |||
|'''8''' | |||
| | |||
|1.531966357 | |||
|738.4615385 | |||
|92.30769231 | |||
| | |||
|1.533793141 | |||
|740.5247079 | |||
|92.56558848 | |||
|- | |||
|'''9''' | |||
| | |||
|1.615866144 | |||
|830.7692308 | |||
|92.30769231 | |||
| | |||
|1.618033989 | |||
|833.0902964 | |||
|92.56558848 | |||
|- | |||
|'''10''' | |||
| | |||
|1.704360793 | |||
|923.0769231 | |||
|92.30769231 | |||
| | |||
|1.706901614 | |||
|925.6558848 | |||
|92.56558848 | |||
|- | |||
|11 | |||
| | |||
|1.797701946 | |||
|1015.384615 | |||
|92.30769231 | |||
| | |||
|1.800650136 | |||
|1018.221473 | |||
|92.56558848 | |||
|- | |||
|12 | |||
| | |||
|1.896155029 | |||
|1107.692308 | |||
|92.30769231 | |||
| | |||
|1.899547627 | |||
|1110.787062 | |||
|92.56558848 | |||
|- | |||
|13 | |||
| | |||
|2 | |||
|1200 | |||
|92.30769231 | |||
| | |||
|2.003876886 | |||
|1203.35265 | |||
|92.56558848 | |||
|} | |} |
Revision as of 00:07, 9 February 2020
Various equal divisions of the octave have close approximations of acoustic phi, or , ≈833.090296357¢. [math]\displaystyle{ φ }[/math]If the [math]\displaystyle{ m^{th} }[/math] step of [math]\displaystyle{ n }[/math]ed2 is a close approximation of [math]\displaystyle{ φ }[/math], the [math]\displaystyle{ n^{th} }[/math] step of [math]\displaystyle{ m }[/math]ed[math]\displaystyle{ φ }[/math] will be a close approximation of 2.
For example, the 7th step of 10ed2 is 840¢, and the 10th step of 7ed[math]\displaystyle{ φ }[/math] is ≈1190.128995¢. As another example, the 9th step of 13ed2 is ≈830.7692308¢, and the 13th step of 9ed[math]\displaystyle{ φ }[/math] is ≈1203.35265¢.
Such [math]\displaystyle{ m }[/math]ed[math]\displaystyle{ φ }[/math] are interesting as variants of their respective [math]\displaystyle{ n }[/math]ed[math]\displaystyle{ 2 }[/math], introducing some combination tone powers.
scale step | 10ed2 | 7edφ or 10ed([math]\displaystyle{ 2^{\frac{10log_2{φ}}{7}} ≈ 1.988629015 }[/math]) | ||||||
frequency multiplier (definition) | 10ed2 frequency multiplier (decimal) | pitch (¢) | Δ (¢) | frequency multiplier (definition) | frequency multiplier (decimal) | pitch (¢) | Δ (¢) | |
1 | [math]\displaystyle{ 2^{\frac{1}{10}} }[/math] | 1.071773463 | 120 | 120 | [math]\displaystyle{ φ^{\frac{1}{7}} }[/math] or [math]\displaystyle{ ≈1.988629015^{\frac{1}{10}} }[/math] | 1.071162542 | 119.0128995 | 119.0128995 |
2 | [math]\displaystyle{ 2^{\frac{2}{10}} }[/math] | 1.148698355 | 240 | 120 | [math]\displaystyle{ φ^{\frac{2}{7}} }[/math] or [math]\displaystyle{ ≈1.988629015^{\frac{2}{10}} }[/math] | 1.147389191 | 238.025799 | 119.0128995 |
3 | [math]\displaystyle{ 2^{\frac{3}{10}} }[/math] | 1.231144413 | 360 | 120 | [math]\displaystyle{ φ^{\frac{3}{7}} }[/math] or [math]\displaystyle{ ≈1.988629015^{\frac{3}{10}} }[/math] | 1.229040323 | 357.0386984 | 119.0128995 |
4 | [math]\displaystyle{ 2^{\frac{4}{10}} }[/math] | 1.319507911 | 480 | 120 | [math]\displaystyle{ φ^{\frac{4}{7}} }[/math] or [math]\displaystyle{ ≈1.988629015^{\frac{4}{10}} }[/math] | 1.316501956 | 476.0515979 | 119.0128995 |
5 | [math]\displaystyle{ 2^{\frac{5}{10}} }[/math] | 1.414213562 | 600 | 120 | [math]\displaystyle{ φ^{\frac{5}{7}} }[/math] or [math]\displaystyle{ ≈1.988629015^{\frac{5}{10}} }[/math] | 1.410187582 | 595.0644974 | 119.0128995 |
6 | [math]\displaystyle{ 2^{\frac{6}{10}} }[/math] | 1.515716567 | 720 | 120 | [math]\displaystyle{ φ^{\frac{6}{7}} }[/math] or [math]\displaystyle{ ≈1.988629015^{\frac{6}{10}} }[/math] | 1.510540115 | 714.0773969 | 119.0128995 |
7 | [math]\displaystyle{ 2^{\frac{7}{10}} }[/math] | 1.624504793 | 840 | 120 | [math]\displaystyle{ φ^{\frac{7}{7}} }[/math] or [math]\displaystyle{ ≈1.988629015^{\frac{7}{10}} }[/math] | 1.618033989 | 833.0902964 | 119.0128995 |
8 | [math]\displaystyle{ 2^{\frac{8}{10}} }[/math] | 1.741101127 | 960 | 120 | [math]\displaystyle{ φ^{\frac{8}{7}} }[/math] or [math]\displaystyle{ ≈1.988629015^{\frac{8}{10}} }[/math] | 1.7331774 | 952.1031958 | 119.0128995 |
9 | [math]\displaystyle{ 2^{\frac{9}{10}} }[/math] | 1.866065983 | 1080 | 120 | [math]\displaystyle{ φ^{\frac{9}{7}} }[/math] or [math]\displaystyle{ ≈1.988629015^{\frac{9}{10}} }[/math] | 1.85651471 | 1071.116095 | 119.0128995 |
10 | [math]\displaystyle{ 2^{\frac{10}{10}} }[/math] | 2 | 1200 | 120 | [math]\displaystyle{ φ^{\frac{10}{7}} }[/math] or [math]\displaystyle{ ≈1.988629015^{\frac{10}{10}} }[/math] | 1.988629015 | 1190.128995 | 119.0128995 |
scale step | 13ed2 | 9edφ or 13ed([math]\displaystyle{ 2^{\frac{10log_2{φ}}{7}} ≈ 1.988629015 }[/math])[math]\displaystyle{ 2^{\frac{10log_2{φ}}{7}} ≈ 1.988629015 }[/math] | ||||||
frequency multiplier (definition) | 10ed2 frequency multiplier (decimal) | pitch (¢) | Δ (¢) | frequency multiplier (definition) | frequency multiplier (decimal) | pitch (¢) | Δ (¢) | |
1 | 1.054766076 | 92.30769231 | 92.30769231 | 1.054923213 | 92.56558848 | 92.56558848 | ||
2 | 1.112531476 | 184.6153846 | 92.30769231 | 1.112862986 | 185.131177 | 92.56558848 | ||
3 | 1.17346046 | 276.9230769 | 92.30769231 | 1.173984997 | 277.6967655 | 92.56558848 | ||
4 | 1.237726285 | 369.2307692 | 92.30769231 | 1.238464025 | 370.2623539 | 92.56558848 | ||
5 | 1.305511698 | 461.5384615 | 92.30769231 | 1.306484449 | 462.8279424 | 92.56558848 | ||
6 | 1.377009451 | 553.8461538 | 92.30769231 | 1.378240772 | 555.3935309 | 92.56558848 | ||
7 | 1.452422856 | 646.1538462 | 92.30769231 | 1.453938184 | 647.9591194 | 92.56558848 | ||
8 | 1.531966357 | 738.4615385 | 92.30769231 | 1.533793141 | 740.5247079 | 92.56558848 | ||
9 | 1.615866144 | 830.7692308 | 92.30769231 | 1.618033989 | 833.0902964 | 92.56558848 | ||
10 | 1.704360793 | 923.0769231 | 92.30769231 | 1.706901614 | 925.6558848 | 92.56558848 | ||
11 | 1.797701946 | 1015.384615 | 92.30769231 | 1.800650136 | 1018.221473 | 92.56558848 | ||
12 | 1.896155029 | 1107.692308 | 92.30769231 | 1.899547627 | 1110.787062 | 92.56558848 | ||
13 | 2 | 1200 | 92.30769231 | 2.003876886 | 1203.35265 | 92.56558848 |