11/8: Difference between revisions

Godtone (talk | contribs)
m consistency
Cleanup on this mess of names: "neutral" tried to convey the same thing as "semiaugmented" but less successfully. "Imperfect" generally means wolf rather than augmented, so "semiperfect" has no basis.
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{{Infobox Interval
{{Infobox Interval
| Name = undecimal superfourth, undecimal neutral fourth, harmonic neutral fourth, harmonic semiaugmented fourth, harmonic semiperfect fourth, Axirabian paramajor fourth, just paramajor fourth, undecimal major fourth, harmonic fourth
| Name = undecimal superfourth, undecimal semiaugmented fourth, harmonic semiaugmented fourth, Axirabian paramajor fourth, just paramajor fourth, undecimal major fourth, harmonic fourth
| Color name = 1o4, ilo 4th
| Color name = 1o4, ilo 4th
| Sound = jid_11_8_pluck_adu_dr220.mp3
| Sound = jid_11_8_pluck_adu_dr220.mp3
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{{Wikipedia|Major fourth and minor fifth}}
{{Wikipedia|Major fourth and minor fifth}}


In [[11-limit]] [[just intonation]], '''11/8''' is an '''undecimal [[superfourth]]''' of about 551.3[[cent|¢]]. This interval is close (~3{{cent}}) to exactly between a [[4/3|perfect fourth]] and [[729/512|augmented fourth]], the latter of which is the ''augmented'' (a.k.a. ''imperfect'') version of the [[Pythagorean tuning|Pythagorean]] [[diatonic]] generator, therefore may be called the '''harmonic semiaugmented/semiperfect fourth''', or '''harmonic/undecimal neutral fourth''' if you prefer to generalise the naming pattern from [[11/9|undecimal neutral third]] and [[12/11|undecimal neutral second]] and their octave-complements (which is also rigorous). Furthermore, as stacks of this interval form a core axis of [[Alpharabian tuning]], it has also been dubbed the '''Axirabian paramajor fourth''' or  more simply the '''just paramajor fourth'''- see [[User:Aura/Aura's Ideas on Functional Harmony #History|the history of Aura's Ideas on Functional Harmony]] for explanation of the modified names. This interval has also been termed the '''undecimal major fourth''' since the tempered version found in [[24edo]] was dubbed the "major fourth" by [[Ivan Wyschnegradsky]], although this may be confusing in diatonic contexts. More recently, [[Zhea Erose]] has suggested calling it something more simple: the '''harmonic fourth''' - under the idea that it is the simplest [[harmonic]] that is in the general (very) rough range of "fourths" when octave-reduced.
In [[11-limit]] [[just intonation]], '''11/8''' is an '''undecimal [[superfourth]]''' of about 551.3{{cent}}. This interval is close (~3{{cent}}) to exactly between a [[4/3|perfect fourth]] and [[729/512|augmented fourth]], the latter of which is the ''augmented'' version of the [[Pythagorean tuning|Pythagorean]] [[diatonic]] generator, therefore may be called the '''harmonic/undecimal semiaugmented fourth'''.  


This interval is the simplest superfourth in JI, and as it falls about halfway between [[12edo]]'s [[perfect fourth]] and [[tritone]], it is very xenharmonic.  As an octave-reduced harmonic, it is a basis of consonance in 11-limit JI, alongside the lower odd numbers 9, 7, 5 and 3. It can be found in harmonic series chords such as 4:5:6:7:8:9:10:11:12, sitting somewhere between the stronger and more familiar consonances of 10 (prime 5) and 12 (prime 3).
This interval is the simplest superfourth in JI, and as it falls about halfway between [[12edo]]'s [[perfect fourth]] and [[tritone]], it is very xenharmonic.  As an octave-reduced harmonic, it is a basis of consonance in 11-limit JI, alongside the lower odd numbers 9, 7, 5 and 3. It can be found in harmonic series chords such as 4:5:6:7:8:9:10:11:12, sitting somewhere between the stronger and more familiar consonances of 10 (prime 5) and 12 (prime 3).
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It is very well-represented in 24edo, making that system especially good for approximations of JI chords involving primes 3 and 11 such as 8:9:11:12.  Not only that, but composers who have experience with 24edo may find it very useful not only as a fantastic addition to major chords, but also as an interesting root motion both for chord progressions within a key and for modulations to key signatures that are not in the same chain of fifths.  Furthermore, these same useful functions can carry over to higher EDOs with good 11-limit representation such as [[159edo]].
It is very well-represented in 24edo, making that system especially good for approximations of JI chords involving primes 3 and 11 such as 8:9:11:12.  Not only that, but composers who have experience with 24edo may find it very useful not only as a fantastic addition to major chords, but also as an interesting root motion both for chord progressions within a key and for modulations to key signatures that are not in the same chain of fifths.  Furthermore, these same useful functions can carry over to higher EDOs with good 11-limit representation such as [[159edo]].


== Terminology ==
The naming pattern from [[11/9|undecimal neutral third]] and [[12/11|undecimal neutral second]] and their octave complements can be rigorously generalized and results in the somewhat unconventional ''harmonic/undecimal neutral fourth''. Furthermore, as stacks of this interval form a core axis of [[Alpharabian tuning]], it has also been dubbed the '''Axirabian paramajor fourth''' or more simply the '''just paramajor fourth''' – see [[User:Aura/Aura's Ideas on Functional Harmony #History|the history of Aura's Ideas on Functional Harmony]] for explanation of the modified names. This interval has also been termed the '''undecimal major fourth''' since the tempered version found in [[24edo]] was dubbed the "major fourth" by [[Ivan Wyschnegradsky]], although this may be confusing in diatonic contexts. More recently, [[Zhea Erose]] has suggested calling it something more simple: the '''harmonic fourth''' – under the idea that it is the simplest [[harmonic]] that is in the general (very) rough range of "fourths" when octave-reduced.


== Approximations by EDOs ==
== Approximations by EDOs ==