11/8: Difference between revisions

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another table, I'm not sure if the decimal places should be reduced deltas can be very small sometimes
m Text replacement - " {{Interval_Edo_Approximation | " to "{{Interval edo approximation|"
 
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{{Infobox Interval
{{Infobox Interval
| Icon =
| Name = undecimal superfourth, harmonic fourth, undecimal tritone, undecimal major fourth, undecimal semiaugmented fourth, harmonic semiaugmented fourth
| Ratio = 11/8
| Monzo = -3 0 0 0 1
| Cents = 551.31794
| Name = undecimal superfourth, <br>major fourth
| Color name = 1o4, ilo 4th
| Color name = 1o4, ilo 4th
| FJS name = P4<sup>11</sup>
| Sound = jid_11_8_pluck_adu_dr220.mp3
| Sound = jid_11_8_pluck_adu_dr220.mp3
}}
}}
{{Wikipedia|Major fourth and minor fifth}}


In [[11-limit]] [[just intonation]], '''11/8''' is an '''undecimal [[superfourth]]''' of about 551.3[[cent|&cent;]]. Falling about halfway between [[12edo]]'s [[perfect fourth]] and [[tritone]], it is very xenharmonic. It is the simplest superfourth in JI. As an octave-reduced overtone, 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 much stronger and more familiar consonances of 10 (prime 5) and 12 (prime 3). 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.
In [[11-limit]] [[just intonation]], '''11/8''' is an '''undecimal [[superfourth|semiaugmented fourth]]''' 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 semiaugmented fourth'''.  


== Approximations by EDOs ==
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).
 
== 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'''. 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.
Because it is right between the diatonic fourth and tritone, it may also be called the '''(lesser) undecimal tritone'''.<ref>Kyle Gann (1998) [https://www.kylegann.com/Octave.html ''Anatomy of an Octave'']</ref>
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.
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'''.
 
== Potential usage ==
 
This interval 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 chord root 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]].


Following [[EDO]]s (up to 200) contain good approximations<ref>error magnitude below 7, both, absolute (in ¢) and relative (in r¢)</ref> of the interval 11/8. Errors are given by magnitude, the arrows in the table show if the EDO representation is sharp (&uarr;) or flat (&darr;).
In more tonal music, 11/8 relative to the tonic ends up being used as the chord root for what amounts to a voicing variation of a 1/1-9/8-225/176-3/2 chord, which, is preceded by a variation on a 1/1-5/4-3/2-225/128 chord built on [[16/15]] relative to the tonic (basically, a type of [[Wikipedia: Neapolitan chord|Neapolitan chord]]), and, followed up by a variation on the 1/1-5/4-3/2-16/9 dominant seventh chord (or potentially even a 1/1-5/4-3/2-16/9-16/15 dominant ninth chord) built on [[3/2]] relative to the tonic for a special type of half cadence. This is a dramatic musical gesture that [[User:Aura|Aura]] has named the "simul half cadence".


{| class="wikitable sortable right-1 center-2 right-3 right-4 center-5"
== Approximations by EDOs ==
|-
{{Interval edo approximation|11/8}}
! [[EDO]]
<references group="note" />
! class="unsortable" | deg\edo
! Absolute <br> error ([[Cent|¢]])
! Relative <br> error ([[Relative cent|r¢]])
! &#8597;
! class="unsortable" | Equally acceptable multiples <ref>Super EDOs up to 200 within the same error tolerance</ref>
|-
|  [[11edo|11]]  ||  5\11  || 5.8634 || 5.3748 || &darr; ||
|-
|  [[13edo|13]]  ||  6\13  || 2.5282 || 2.7389 || &uarr; || [[26edo|12\26]]
|-
|  [[24edo|24]]  ||  11\24  || 1.3179 || 2.6359 || &darr; || [[48edo|22\48]]
|-
|  [[37edo|37]]  ||  17\37  || 0.0334 || 0.1030 || &uarr; || [[74edo|34\74]], [[111edo|51\111]], [[148edo|68\148]], [[185edo|85\185]]
|-
|  [[50edo|50]]  ||  23\50  || 0.6821 || 2.8419 || &uarr; || [[100edo|46\100]]
|-
|  [[61edo|61]]  ||  28\61  || 0.4983 || 2.5329 || &darr; || [[122edo|56\122]]
|-
|  [[63edo|63]]  ||  29\63  || 1.0630 || 5.5808 || &uarr; ||
|-
|  [[85edo|85]]  ||  39\85  || 0.7297 || 5.1688 || &darr; ||
|-
|  [[87edo|87]]  ||  40\87  || 0.4062 || 2.9449 || &uarr; || [[174edo|80\174]]
|-
|  [[98edo|98]]  ||  45\98  || 0.2975 || 2.4299 || &darr; || [[196edo|90\196]]
|-
| [[124edo|124]] ||  57\124 || 0.2950 || 3.0479 || &uarr; ||
|-
| [[135edo|135]] ||  62\135 || 0.2068 || 2.3269 || &darr; ||
|-
| [[137edo|137]] ||  63\137 || 0.5069 || 5.7868 || &uarr; ||
|-
| [[159edo|159]] ||  73\159 || 0.3745 || 4.9627 || &darr; ||
|-
| [[161edo|161]] ||  74\161 || 0.2349 || 3.1509 || &uarr; ||
|-
| [[172edo|172]] ||  79\172 || 0.1552 || 2.2238 || &darr; ||
|-
| [[198edo|198]] ||  91\198 || 0.1972 || 3.2540 || &uarr; ||
|-
|}


== See also ==
== See also ==
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* [[Gallery of just intervals]]
* [[Gallery of just intervals]]


[[Category:11-limit]]
== References ==
[[Category:Interval ratio]]
<references />
 
[[Category:Fourth]]
[[Category:Superfourth]]
[[Category:Superfourth]]
[[Category:Fourth]]
[[Category:Alpharabian]]
[[Category:Listen]]
[[Category:Untwelve]]
[[Category:Overtone]]
[[Category:Over-2]]