Diminished seventh chord: Difference between revisions
The Starling chord appears to be 7-odd, not 9-odd. |
Emphasize that the temperament representations are specifically dealing with stacks of ~6/5 minor thirds. (I haven't looked at non-meantone temperaments that also handle 32/27 in an interesting way.) |
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== In temperaments == | == In temperaments == | ||
If [[648/625]] is [[tempering out|tempered out]], as in the [[dimipent]] temperament (loosely named for this chord), a ~[[36/25]] diminished fifth is equated with its [[complement]] (~[[25/18]]), | If [[648/625]] is [[tempering out|tempered out]], as in the [[dimipent]] temperament (loosely named for this chord), a stack of three [[~]][[6/5]] minor thirds is tempered to leave another ~6/5 to close the octave. The ~[[36/25]] diminished fifth is equated with its [[complement]] (~[[25/18]]), and the ~[[216/125]] diminished seventh is equated with a ~[[5/3]] major sixth, forming a [[25-odd-limit]] [[essentially tempered chord]]: | ||
* (Dimipent) 1 – 6/5 – 25/18 – 5/3 | * (Dimipent) 1 – 6/5 – 25/18 – 5/3 | ||
If [[36/35]] is also tempered out, giving [[Diminished (temperament)|diminished temperament]] (also named for this chord), the ~ | If [[36/35]] is also tempered out, giving [[Diminished (temperament)|diminished temperament]] (also named for this chord), the ~36/25 diminished fifth is equated with ~[[7/5]], and the stack of ~6/5 thirds becomes a [[7-odd-limit]] [[essentially tempered chord]]: | ||
* (Diminished) 1 – 6/5 – 7/5 – 5/3 | * (Diminished) 1 – 6/5 – 7/5 – 5/3 | ||
(Note that the interval of ~[[25/18]] between ~6/5 and ~5/3 tempers to ~[[10 | (Note that the interval of ~[[25/18]] between ~6/5 and ~5/3 tempers to ~[[10/7]].) | ||
In 5-limit [[meantone]], which tempers out [[81/80]], a stack of three minor thirds tempers to ~[[128/75]], leaving a ~[[75/64]] augmented second to close the octave. The resulting chord has an [[intervallic odd limit]] of 75: | In 5-limit [[meantone]], which tempers out [[81/80]], a stack of three ~6/5 minor thirds tempers to ~[[128/75]], leaving a ~[[75/64]] augmented second to close the octave. The resulting chord has an [[intervallic odd limit]] of 75: | ||
* (Meantone) 1 – 6/5 – 36/25 – 128/75 | * (Meantone) 1 – 6/5 – 36/25 – 128/75 |