Diminished seventh chord: Difference between revisions

Followup
Bcmills (talk | contribs)
move Diminished / Dimipent temperament discussion into a section; add Diminished temperament chord; stub out some JI chords
Line 1: Line 1:
{{Wikipedia}}
{{Wikipedia}}


The '''diminished seventh chord''' is a [[tetrad]] traditionally described as comprising a root, [[minor]] third, [[interval quality|diminished]] fifth, and diminished seventh. In contemporary [[12edo]] music, it is a stack of four identical minor thirds of [[~]][[6/5]] closing at the [[octave]], [[tempering out]] [[648/625]]. In the 5-limit, the simplest interpretation is a [[25-odd-limit]] [[essentially tempered chord]] of the [[dimipent]] temperament, the temperament named after this chord.  
The '''diminished seventh chord''' is a [[tetrad]] comprising a root, [[minor]] third, [[interval quality|diminished]] fifth, and diminished seventh, conventionally formed by stacking three minor thirds.
* (Dimipent) 1 – 6/5 – 25/18 – 5/3, with steps 6/5, 6/5, 6/5, 6/5.
 
== In temperaments ==
 
In [[Diminished (temperament)|diminished temperament]], which is named for this chord and [[tempering out|tempers out]] both [[648/625]] and [[36/35]], the ~[[36/25]] diminished fifth is equivalent to ~[[7/5]], and the ~[[216/125]] diminished seventh is equivalent to a ~[[5/3]] major sixth, giving rise to a [[7-odd-limit]] [[essentially tempered chord]]:
 
* (Diminished) 1 – 6/5 – 7/5 – 5/3
 
(Note that the interval between ~6/5 and ~5/3 tempers to ~10/7.)
 
In the 5-limit, the simplest interpretation as a stack of ~6/5 is a [[25-odd-limit]] [[essentially tempered chord]] of the [[dimipent]] temperament, another temperament named after this chord.  
 
* (Dimipent) 1 – 6/5 – 25/18 – 5/3


== In meantone ==
== In meantone ==
Before the ubiquity of [[12edo]], a diminished seventh chord did not imply an equal tuning of all four thirds (technically three minor thirds and an augmented second). It can be viewed as a 9-odd-limit essentially tempered chord of [[starling]]. See [[starling chords]]. This is still compatible with 12edo and is perhaps as authentic as the 25-odd-limit interpretation above.


Before the ubiquity of [[12edo]], a diminished seventh chord did not imply an equal tuning of all four thirds (technically three minor thirds and an augmented second). It can be viewed as a 9-odd-limit essentially tempered chord of [[starling]]. See [[starling chords]]. This is still compatible with 12edo and is perhaps as authentic as the 25-odd-limit interpretation above.
<!-- This needs more detail. What is the actual starling chord in question, and how does this relate in any way to (especially 5-limit) meantone? -->
== In just intonation ==
* [[10:12:14:17]] <!-- Wikipedia: François-Joseph Fétis -->
* [[125:150:180:216]] <!-- stacked minor thirds -->
* [[225:270:320:384]] <!-- Wikipedia: “incomplete dominant ninth”, and found in the duodene. -->


{{Stub}}
{{stub}}


[[Category:Just intonation chords]]
[[Category:Just intonation chords]]
[[Category:Diminished seventh chords| ]] <!-- main article -->
[[Category:Diminished seventh chords| ]] <!-- main article -->
[[Category:Diminished]]
[[Category:Essentially tempered chords]]
[[Category:7-odd-limit chords]]