27/20: Difference between revisions

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{{Infobox Interval

~~| Icon =~~

| Name = wolf fourth, classic acute fourth

~~| Ratio = 27/20~~

| Color name = g4, gu 4th

~~| Monzo = -2 3 -1~~

~~| Cents = 519.55129~~

| Name = wolf fourth

| Color name =

~~| FJS name = P4<sub>5</sub>~~

| Sound = jid_27_20_pluck_adu_dr220.mp3

}}

In [[5-limit]] [[just intonation]], '''27/20''' is an interval measuring about 519.6¢. It differs from the [[4/3]] perfect fourth by [[81/80]] (about 21.5¢), the syntonic comma. It arises naturally in JI as (for instance) the difference between a 5-limit major third and a stack of five [[3/2]] perfect fifths, or as the interval between [[10/9]] and [[3/2]]. In [[12edo]] and [[meantone]] systems, this interval would be no different from 4/3, as the syntonic comma is tempered out. 27/20 has been described as a "wolf" interval, implying that it "howls," as compared to simpler intervals within the 5-limit such as [[5/4]] and [[9/8]]. Although in a 5-limit context it is traditionally avoided, it can be an essential interval in a harmonic context of higher complexity, where it may be admired for its bright and active character and its distinctness from 4/3.

In [[5-limit]] [[just intonation]], '''27/20''', the '''classic acute fourth''', is an interval measuring about 519.6{{cent}}. It differs from the [[4/3]] perfect fourth by [[81/80]] (about 21.5{{cent}}), the syntonic comma. It arises naturally in JI as (for instance) the difference between a 5-limit major third and a stack of five [[3/2]] perfect fifths, or as the interval between [[10/9]] and [[3/2]]. In [[12edo]] and [[meantone]] systems, this interval would be no different from 4/3, as the syntonic comma is tempered out. 27/20 has been described as a "wolf" interval, implying that it "howls", as compared to simpler intervals within the 5-limit such as [[5/4]] and [[9/8]]. Although in a 5-limit context it is traditionally avoided, it can be an essential interval in a harmonic context of higher complexity, where it may be admired for its bright and active character and its distinctness from 4/3.

== Approximation ==

== Trivia ==

This ratio is the difference between two common record speeds (45 rpm and "33" rpm). As such, alterations by this interval often occur when a record is played at the wrong speed.

== See also ==

* [[40/27]] – its [[octave complement]]

* [[10/9]] – its [[fifth complement]]

* [[Gallery of just intervals]]

~~[[Category:5-limit]]~~

[[Category:Fourth]]

~~[[Category:Listen]]~~

@@ Line 1: / Line 1: @@
 {{Infobox Interval
-| Icon =
+| Name = wolf fourth, classic acute fourth
-| Ratio = 27/20
+| Color name = g4, gu 4th
-| Monzo = -2 3 -1
-| Cents = 519.55129
-| Name = wolf fourth
-| Color name =
-| FJS name = P4<sub>5</sub>
 | Sound = jid_27_20_pluck_adu_dr220.mp3
 }}
-In [[5-limit]] [[just intonation]], '''27/20''' is an interval measuring about 519.6¢. It differs from the [[4/3]] perfect fourth by [[81/80]] (about 21.5¢), the syntonic comma. It arises naturally in JI as (for instance) the difference between a 5-limit major third and a stack of five [[3/2]] perfect fifths, or as the interval between [[10/9]] and [[3/2]]. In [[12edo]] and [[meantone]] systems, this interval would be no different from 4/3, as the syntonic comma is tempered out. 27/20 has been described as a "wolf" interval, implying that it "howls," as compared to simpler intervals within the 5-limit such as [[5/4]] and [[9/8]]. Although in a 5-limit context it is traditionally avoided, it can be an essential interval in a harmonic context of higher complexity, where it may be admired for its bright and active character and its distinctness from 4/3.
+In [[5-limit]] [[just intonation]], '''27/20''', the '''classic acute fourth''', is an interval measuring about 519.6{{cent}}. It differs from the [[4/3]] perfect fourth by [[81/80]] (about 21.5{{cent}}), the syntonic comma. It arises naturally in JI as (for instance) the difference between a 5-limit major third and a stack of five [[3/2]] perfect fifths, or as the interval between [[10/9]] and [[3/2]]. In [[12edo]] and [[meantone]] systems, this interval would be no different from 4/3, as the syntonic comma is tempered out. 27/20 has been described as a "wolf" interval, implying that it "howls", as compared to simpler intervals within the 5-limit such as [[5/4]] and [[9/8]]. Although in a 5-limit context it is traditionally avoided, it can be an essential interval in a harmonic context of higher complexity, where it may be admired for its bright and active character and its distinctness from 4/3.
+== Approximation ==
+{{Interval edo approximation|27/20}}
+== Trivia ==
+This ratio is the difference between two common record speeds (45 rpm and "33" rpm). As such, alterations by this interval often occur when a record is played at the wrong speed.
 == See also ==
 * [[40/27]] – its [[octave complement]]
 * [[10/9]] – its [[fifth complement]]
 * [[Gallery of just intervals]]
-[[Category:5-limit]]
 [[Category:Fourth]]
-[[Category:Listen]]