20:25:30:36: Difference between revisions

20:25:30:36, a major-minor seventh chord, is a tetrad in 5-limit harmony, and sometimes considered a form of dominant seventh chord. It combines a 5/4 major third with the consonant 9/5 seventh that would be found in a Ptolemaic minor seventh chord on the same root, creating a 36/25 tritone between the two.

The major-minor seventh chord is found rooted at the I (1⁄1) and IV (4⁄3) of the duodene.

In meantone, the ~9/5 seventh is equated with 16/9, making this chord equivalent to the meantone tuning of 36:45:54:64.

In septimal meantone, the ~36/25 tritone is equated with the more consonant interval 10/7, and the major-minor seventh chord becomes an essentially tempered chord in the 9-odd-limit.

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 The major-minor seventh chord is found rooted at the I ({{Frac|1|1}}) and IV ({{Frac|4|3}}) of the [[duodene]].
-In [[Meantone_family#Septimal_meantone|septimal meantone]], the 36/25 tritone is equated with the more consonant interval [[10/7]], and the major-minor seventh chord becomes an [[essentially tempered chord]] in the [[9-odd-limit]].
+In [[meantone]], the ~[[9/5]] seventh is equated with [[16/9]], making this chord equivalent to the meantone tuning of [[36:45:54:64]].
+In [[septimal meantone]], the ~36/25 tritone is equated with the more consonant interval [[10/7]], and the major-minor seventh chord becomes an [[essentially tempered chord]] in the [[9-odd-limit]].
 [[Category:Dominant seventh chords|##]] <!-- 2-digit first number -->

Revision as of 00:39, 28 August 2024