27/20: Difference between revisions
m Text replacement - " {{Interval_Edo_Approximation | " to "{{Interval edo approximation|" |
m →Trivia |
||
| (2 intermediate revisions by 2 users not shown) | |||
| Line 7: | Line 7: | ||
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. | 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 == | == Approximation == | ||
{{Interval edo approximation|27/20} | {{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 == | == See also == | ||
* [[40/27]] – its [[octave complement]] | * [[40/27]] – its [[octave complement]] | ||