730edo: Difference between revisions
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{{Infobox ET | |||
| Prime factorization = 2 × 5 × 73 | |||
| Step size = 1.64384¢ | |||
| Fifth = 427\730 (701.92¢) | |||
| Semitones = 69:55 (113.42¢ : 90.41¢) | |||
| Consistency = 15 | |||
}} | |||
{{EDO intro|730}} | |||
== Theory == | |||
730edo is a very strong 5-limit system, but is also distinctly consistent up to the [[15-odd-limit]]. It tempers out the [[counterschisma]], {{monzo| -69 45 -1 }}, the minortone comma, {{monzo| -16 35 -17 }}, the kwazy comma, {{monzo| -53 10 16 }}, the whoosh comma, {{monzo| 37 25 -33 }}, and the pirate comma, {{monzo| -90 -15 49 }}. In the 7-limit it tempers out [[4375/4374]] and {{monzo| -21 0 3 5 }}, so that it [[support]]s the [[mitonic]] temperament. In the 11-limit, [[3025/3024]] and {{monzo| 4 -3 -6 4 1 }}, so that it supports the [[deca]] temperament. In the 13-limit, [[1001/1000]] and [[4225/4224]], supporting 13-limit deca. | |||
{{ | [[W. S. B. Woolhouse]] proposed 730edo<ref name="summary">[http://www.webcitation.org/5zxZzQ3eS A summary of W. S. B. Woolhouse's Essay on musical intervals], 1999 by [[Joe Monzo]]</ref> as a [[Interval size measure|logarithmic measure of interval size]], sometimes called the '''Woolhouse unit'''. While 730 is divisible by 2, 5, 10, 73, 146 and 365, it is not divisible by 12, which can be regarded as either a good thing or a bad one. | ||
=== Prime harmonics === | |||
{{Harmonics in equal|730|columns=11}} | |||
== Intervals == | == Intervals == | ||
W. S. B. Woolhouse, in his 1835 essay<ref name="essay">[https://archive.org/details/essayonmusicali00woolgoog/page/n34/mode/2up Essay on musical intervals, harmonics, and the temperament of the musical scale, &c], 1835 by Wesley Stoker Barker Woolhouse</ref>, proposed: | W. S. B. Woolhouse, in his 1835 essay<ref name="essay">[https://archive.org/details/essayonmusicali00woolgoog/page/n34/mode/2up Essay on musical intervals, harmonics, and the temperament of the musical scale, &c], 1835 by Wesley Stoker Barker Woolhouse</ref>, proposed: | ||
<blockquote> | <blockquote> | ||
… dividing the octave into 730 equal intervals, which we shall call ''degrees'', the elemental intervals will be: | |||
<pre> | <pre> | ||
Major-tone, t = 124 | Major-tone, t = 124 | ||
| Line 17: | Line 27: | ||
Comma, c = 13 | Comma, c = 13 | ||
</pre> | </pre> | ||
… | |||
These numbers present a more accurate measurement of the musical scale than any other, unless we go to very high numbers. The greatest error which can arise from their natural or melodious combinations is that of the fifth, and does not amount to one half of the error of the major-tone above mentioned. | These numbers present a more accurate measurement of the musical scale than any other, unless we go to very high numbers. The greatest error which can arise from their natural or melodious combinations is that of the fifth, and does not amount to one half of the error of the major-tone above mentioned. | ||
| Line 33: | Line 43: | ||
</blockquote> | </blockquote> | ||
== Woolhouse diatonic scale == | == Scales == | ||
=== Woolhouse diatonic scale === | |||
Woolhouse defined the following diatonic/heptonic scale for 730edo<ref name="essay" />. | Woolhouse defined the following diatonic/heptonic scale for 730edo<ref name="essay" />. | ||
| Line 85: | Line 95: | ||
== References == | == References == | ||
<references /> | <references /> | ||
[[Category:Equal divisions of the octave|###]] <!-- 3-digit number --> | [[Category:Equal divisions of the octave|###]] <!-- 3-digit number --> | ||
Revision as of 15:48, 16 August 2022
| ← 729edo | 730edo | 731edo → |
Theory
730edo is a very strong 5-limit system, but is also distinctly consistent up to the 15-odd-limit. It tempers out the counterschisma, [-69 45 -1⟩, the minortone comma, [-16 35 -17⟩, the kwazy comma, [-53 10 16⟩, the whoosh comma, [37 25 -33⟩, and the pirate comma, [-90 -15 49⟩. In the 7-limit it tempers out 4375/4374 and [-21 0 3 5⟩, so that it supports the mitonic temperament. In the 11-limit, 3025/3024 and [4 -3 -6 4 1⟩, so that it supports the deca temperament. In the 13-limit, 1001/1000 and 4225/4224, supporting 13-limit deca.
W. S. B. Woolhouse proposed 730edo[1] as a logarithmic measure of interval size, sometimes called the Woolhouse unit. While 730 is divisible by 2, 5, 10, 73, 146 and 365, it is not divisible by 12, which can be regarded as either a good thing or a bad one.
Prime harmonics
| Harmonic | 2 | 3 | 5 | 7 | 11 | 13 | 17 | 19 | 23 | 29 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Error | Absolute (¢) | +0.000 | -0.037 | -0.012 | -0.607 | -0.633 | -0.528 | +0.250 | +0.021 | -0.329 | -0.536 | +0.718 |
| Relative (%) | +0.0 | -2.3 | -0.8 | -36.9 | -38.5 | -32.1 | +15.2 | +1.3 | -20.0 | -32.6 | +43.7 | |
| Steps (reduced) |
730 (0) |
1157 (427) |
1695 (235) |
2049 (589) |
2525 (335) |
2701 (511) |
2984 (64) |
3101 (181) |
3302 (382) |
3546 (626) |
3617 (697) | |
Intervals
W. S. B. Woolhouse, in his 1835 essay[2], proposed:
… dividing the octave into 730 equal intervals, which we shall call degrees, the elemental intervals will be:
Major-tone, t = 124 Minor-tone, tˌ= 111 Limma, θ = 68 Comma, c = 13…
These numbers present a more accurate measurement of the musical scale than any other, unless we go to very high numbers. The greatest error which can arise from their natural or melodious combinations is that of the fifth, and does not amount to one half of the error of the major-tone above mentioned.
The concordant intervals are
Minor-third ...... 192 Major-third ...... 235 Fourth ........... 303 Fifth ............ 427 Minor-sixth ...... 495 Major-sixth ...... 538 Octave ........... 730
Scales
Woolhouse diatonic scale
Woolhouse defined the following diatonic/heptonic scale for 730edo[2].
According to this division of the octave into 730 degrees, which we shall here-after adopt, the diatonic scale will be —
Key ... 0 ... 124 ... t ... Major-tone. 2d ... 124 ... 111 ... tˌ... Minor-tone. 3d ... 235 ... 68 ... θ ... Limma. 4th ... 303 ... 124 ... t ... Major-tone. 5th ... 427 ... 111 ... tˌ... Minor-tone. 6th ... 538 ... 124 ... t ... Major-tone. 7th ... 662 ... 68 ... θ ... Limma. 8th ... 730
Woolhouse's diatonic scale in Ls notation is
- LMsLMLs - L: 124, M: 111, s: 68
Inferred modes are shown in the following table.
| Sequence | Mode (suggested name) | I1 | I2 | I3 | I4 | I5 | I6 | I7 |
|---|---|---|---|---|---|---|---|---|
| LMsLMLs | Woolhouse Ionian | P1 | M2 | M35 | P4 | P5 | M65 | M75 |
| MsLMLsL | Woolhouse Dorian | P1 | m25 | m35 | P4 | P5 | m65 | m75 |
| sLMLsLM | Woolhouse Phrygian | P1 | M25 | M35 | P4 | P5 | M65 | m7 |
| LMLsLMs | Woolhouse Lydian | P1 | m25 | m35 | P4 | d517 | m65 | m7 |
| MLsLMsL | Woolhouse Mixolydian | P1 | M25 | m319 | P4 | - | M65 | m7 |
| LsLMsLM | Woolhouse Aeolian | P1 | M2 | M35 | A45 | P5 | d7175 | M75 |
| sLMsLML | Woolhouse Locrian | P1 | M2 | m35 | P4197 | P5 | m65 | m75 |
References
- ↑ A summary of W. S. B. Woolhouse's Essay on musical intervals, 1999 by Joe Monzo
- ↑ 2.0 2.1 Essay on musical intervals, harmonics, and the temperament of the musical scale, &c, 1835 by Wesley Stoker Barker Woolhouse