User:Moremajorthanmajor/Ed9/4: Difference between revisions
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Division of 9/4 into equal parts does not necessarily imply directly using this interval as an [[equivalence]]. Many, though not all, ed9/4 scales have a perceptually important [[Pseudo-octave|false octave]], with various degrees of accuracy. | Division of 9/4 into equal parts does not necessarily imply directly using this interval as an [[equivalence]]. Many, though not all, ed9/4 scales have a perceptually important [[Pseudo-octave|false octave]], with various degrees of accuracy. | ||
The structural utility of 9/4 or another major ninth is apparent by being the standard replacement for the root in jazz piano voicings. Also, as a ninth is the double of a fifth, the fifth of normal root position triads will become the common suspension (5-4 or 5-6) of a ninth-based system | The structural utility of 9/4 or another major ninth is apparent by being the standard replacement for the root in jazz piano voicings. Also, as a ninth is the double of a fifth, the fifth of normal root position triads will become the common suspension (5-4 or 5-6) of a ninth-based system. | ||
== Josrph Ruhf's ed9/4 theory== | == Josrph Ruhf's ed9/4 theory== | ||
{{idiosyncratic terms}} | {{idiosyncratic terms}} | ||
In ed9/4 systems, thirds and sixths are no longer inverses, and thus an [[Pseudo-traditional harmonic functions of octatonic scale degrees|octatonic scale]] (i. e. any of those of the proper Napoli temperament family, which are generated by a fourth optionally with a period equivalent to three or six macrotones, in particular ones at least as wide as 101.083 cents) takes 1-3-6, which is not equivalent to a tone cluster as it would be in an edf tuning, as the root position of its regular triad. | |||
One way to approach some ed9/4 tunings is the use of the 5:6:8 chord as the fundamental complete sonority in a very similar way to the 4:5:6:(8) chord in meantone. Whereas in meantone it takes four 3/2 to get to 5/1, here it takes four 9/8 to get to 8/5 (tempering out the schisma). So, doing this yields 6-, 8-, 14- and 20- or 22-note [[2mos]]. While the notes are rather farther apart, the scheme is superficially similar to certain versions of the regularly tempered approximate ("full"-status) [[A shruti list|shrutis]]. [[Joseph Ruhf]] proposes the name "macroshrutis" for this reason. | One way to approach some ed9/4 tunings is the use of the 5:6:8 chord as the fundamental complete sonority in a very similar way to the 4:5:6:(8) chord in meantone. Whereas in meantone it takes four 3/2 to get to 5/1, here it takes four 9/8 to get to 8/5 (tempering out the schisma). So, doing this yields 6-, 8-, 14- and 20- or 22-note [[2mos]]. While the notes are rather farther apart, the scheme is superficially similar to certain versions of the regularly tempered approximate ("full"-status) [[A shruti list|shrutis]]. [[Joseph Ruhf]] proposes the name "macroshrutis" for this reason. | ||