French sixth chord: Difference between revisions

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In temperaments: clarify conventional / septimal meantone distinction; refer to starling instead of marvel for the general essentially-tempered chord (marvel doesn't get that close!)
Undo revision 176740 by MisterShafXen (talk). This was just false
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* ([[Septimal meantone chords|Septimal meantone]]) 1 – 5/4 – 7/5 – 7/4
* ([[Septimal meantone chords|Septimal meantone]]) 1 – 5/4 – 7/5 – 7/4


or [[20:25:28:35]] (step sizes 5/4, 28/25, and 5/4). Since the [[28/25]] interval in this chord also represents [[10/9]], in septimal meantone (and, more generally, in [[starling]] temperaments) this chord is an [[essentially tempered chord]] in the [[9-odd-limit]].
or [[20:25:28:35]] (step sizes 5/4, 28/25, and 5/4). Since the [[28/25]] interval in this chord also represents [[9/8]] in septimal meantone and [[marvel]], and [[10/9]] in septimal meantone and [[starling]], this chord is an [[essentially tempered chord]] in those temperaments in the [[9-odd-limit]].
<!-- Note: The close approximation of the 7-limit chord is specific to quarter-comma meantone. Many other meantones, such as 12edo and 19edo, do not approximate it nearly as closely, although they may nonetheless support the septimal meantone interpretation that unifies it with the French sixth. -->
<!-- Note: The close approximation of the 7-limit chord in meantone is specific to quarter-comma meantone. Many other meantones, such as 12edo and 19edo, do not approximate it nearly as closely, although they may nonetheless support the septimal meantone interpretation that unifies it with the French sixth. -->


== In just intonation ==
== In just intonation ==
In the [[7-limit]]:
* [[20:25:28:35]] is a [[condissonant]] chord corresponding to an interpretation of the French sixth found in starling and marvel temperaments.


In the [[5-limit]]:
In the [[5-limit]]:


* [[128:160:180:225]],  one of the possible 5-limit interpretations of the meantone chord, is found rooted at ♭II ({{Frac|16|15}}) and ♭VI ({{Frac|8|5}}) in the [[duodene]].
* [[128:160:180:225]],  one of the possible 5-limit interpretations of the meantone chord, is found rooted at ♭II ({{Frac|16|15}}) and ♭VI ({{Frac|8|5}}) in the [[duodene]].
* [[72:90:100:125]], another possible interpretation of the meantone chord, is found in [[Euler-Fokker genus|genus]] 3²&#xb7;5³.
== See also ==
* [[Dominant seventh flat five chord]], a chord that is enharmonically equivalent to a French sixth in 12edo.
   
   
[[Category:French sixth chords| ]] <!-- main article -->
[[Category:French sixth chords| ]] <!-- main article -->

Latest revision as of 15:07, 17 January 2025

A French sixth chord is a tetrad comprising a root, major third, augmented fourth, and augmented sixth.

In temperaments

In 5-limit meantone, the traditional foundation of tonal harmony, the augmented sixth represents both 225/128 and 125/72, and the augmented fourth represents all of 45/32, 25/18, and 729/512, so the 5-limit meantone French sixth chord,

  • (Meantone) 1 – 5/4 – 25/18 – 125/72

represents a range of JI interpretations including both 72:90:100:125 (step sizes 5/4, 10/9, and 5/4) and 128:160:180:225 (step sizes 5/4, 9/8, and 5/4).

However, in the historically prevalent quarter-comma meantone, the augmented sixth is tuned only a few cents shy of a just 7/4, and the augmented fourth is only a few cents shy of 7/5, so the meantone French sixth chord can be considered to also approximate the septimal meantone chord:

or 20:25:28:35 (step sizes 5/4, 28/25, and 5/4). Since the 28/25 interval in this chord also represents 9/8 in septimal meantone and marvel, and 10/9 in septimal meantone and starling, this chord is an essentially tempered chord in those temperaments in the 9-odd-limit.

In just intonation

In the 7-limit:

  • 20:25:28:35 is a condissonant chord corresponding to an interpretation of the French sixth found in starling and marvel temperaments.

In the 5-limit:

  • 128:160:180:225, one of the possible 5-limit interpretations of the meantone chord, is found rooted at ♭II (1615) and ♭VI (85) in the duodene.
  • 72:90:100:125, another possible interpretation of the meantone chord, is found in genus 3²·5³.

See also