23edo: Difference between revisions
Dave Keenan (talk | contribs) →Second best fifth notation: Hyphenated "Second-best" in the heading, to agree with the image. |
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{{EDO intro|23}} | {{EDO intro|23}} | ||
== Theory == | == Theory == | ||
=== Harmonics === | |||
{{Harmonics in equal|23}} | {{Harmonics in equal|23}} | ||
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23edo was proposed by ethnomusicologist [[Wikipedia: Erich von Hornbostel|Erich von Hornbostel]] as the result of continuing a circle of "blown" fifths of ~678-cent fifths that (he argued) resulted from "overblowing" a bamboo pipe. | 23edo was proposed by ethnomusicologist [[Wikipedia: Erich von Hornbostel|Erich von Hornbostel]] as the result of continuing a circle of "blown" fifths of ~678-cent fifths that (he argued) resulted from "overblowing" a bamboo pipe. | ||
23edo is also significant in that it is the largest edo that fails to approximate the 3rd, 5th, 7th, and 11th harmonics within 20 cents, which makes it well-suited for musicians seeking to explore harmonic territory that is unusual even for the average microtonalist. Oddly, despite the fact that it fails to approximate these harmonics, it approximates the intervals between them ([[5/3]], [[7/3]], [[11/3]], [[7/5]], [[11/5]], [[11/7]]) and combinations of them ([[15/8]], [[21/16]], [[33/32]], [[35/32]], [[55/32]], [[77/64]]) very well. The lowest harmonics well-approximated by 23edo are 9, 13, 15, 17, 21, 23, 31, 33 and 35 | 23edo is also significant in that it is the largest edo that fails to approximate the 3rd, 5th, 7th, and 11th harmonics within 20 cents, which makes it well-suited for musicians seeking to explore harmonic territory that is unusual even for the average microtonalist. Oddly, despite the fact that it fails to approximate these harmonics, it approximates the intervals between them ([[5/3]], [[7/3]], [[11/3]], [[7/5]], [[11/5]], [[11/7]]) and combinations of them ([[15/8]], [[21/16]], [[33/32]], [[35/32]], [[55/32]], [[77/64]]) very well. The lowest harmonics well-approximated by 23edo are 9, 13, 15, 17, 21, 23, 31, 33 and 35. | ||
See ''[[Harmony of 23edo]]'' for more details. | |||
Also note that some approximations can be improved by octave stretching. See ''[[23edo and octave stretching]]'' for more details. | |||
=== Mapping === | |||
As with [[9edo]], [[16edo]], and [[25edo]], one way to treat 23edo is as a tuning of the [[pelogic]] temperament, tempering out the "comma" of [[135/128]] and equating three acute [[4/3]]'s with 5/1 (related to the Armodue system). This means mapping "[[3/2]]" to 13 degrees of 23, and results in a 7 notes [[2L 5s|antidiatonic scale]] of 3 3 4 3 3 3 4 (in steps of 23edo), which extends to 9 notes [[7L 2s|superdiatonic scale]] (3 3 3 1 3 3 3 3 1). One can notate 23edo using the [[Armodue]] system, but just like notating 17edo with familiar diatonic notation, flats will be lower in pitch than enharmonic sharps, because in 23edo, the "Armodue 6th" is sharper than it is in 16edo, just like the diatonic 5th in 17edo is sharper than in 12edo. In other words, 2b is lower in pitch than 1#, just like how in 17edo Eb is lower than D#. | As with [[9edo]], [[16edo]], and [[25edo]], one way to treat 23edo is as a tuning of the [[pelogic]] temperament, tempering out the "comma" of [[135/128]] and equating three acute [[4/3]]'s with 5/1 (related to the Armodue system). This means mapping "[[3/2]]" to 13 degrees of 23, and results in a 7 notes [[2L 5s|antidiatonic scale]] of 3 3 4 3 3 3 4 (in steps of 23edo), which extends to 9 notes [[7L 2s|superdiatonic scale]] (3 3 3 1 3 3 3 3 1). One can notate 23edo using the [[Armodue]] system, but just like notating 17edo with familiar diatonic notation, flats will be lower in pitch than enharmonic sharps, because in 23edo, the "Armodue 6th" is sharper than it is in 16edo, just like the diatonic 5th in 17edo is sharper than in 12edo. In other words, 2b is lower in pitch than 1#, just like how in 17edo Eb is lower than D#. | ||