Septimal meantone temperament
This article includes a improve this article by introducing more precise citations. (June 2008) ) |
In music, septimal meantone temperament, also called standard septimal meantone or simply septimal meantone, refers to the
Choice of temperament
Meantone temperament produces a frequency ratio of approximately 5 by means of four fifths, so that the major third (for instance C–E) is obtained from two successive whole tones.
Septimal meantone produces the frequency ratio of 56 ( 7 × 23 ) by ten fifths, so that the interval 7:4 is reached by five successive tones. Hence C–A♯, not C–B♭, represents a 7:4 interval in septimal meantone.
There are several slightly adjusted meantone tunings very nearly equivalent to exact
Temperament goal Temperament name Size of fifth Audio example pure 5:4 intervals quarter-comma meantone 696.58 cents ⓘ pure 7:4 intervals modified quarter tone 696.88 cents ⓘ uniform intervals in every key 31 equal temperament 696.77 cents ⓘ
31 equal temperament does excellently for both of the others: It has augmented sixths only 1.1 cent flat of a purely harmonic seventh, and its major third is only 1.2 cents sharper than a pure fifth harmonic; while the fifth is 5.2 cents flat from the third harmonic. The differences are so small that the distinction is mainly academic.[citation needed]
Theoretical properties
Septimal meantone tempers out not only the syntonic comma of 81:80, but also the septimal semicomma of 126:125, and the septimal kleisma of 225:224 . Because the septimal semicomma is tempered out, a chord with intervals 6:5 – 6:5 – 6:5 – 7:6, spanning the octave, is a part of the septimal meantone tuning system. This chord might be called the septimal semicomma diminished seventh. Similarly, because the septimal kleisma is tempered out, a chord with intervals of size 5:4 – 5:4 – 9:7 spans the octave; this might be called the septimal kleisma augmented triad, and is likewise a characteristic feature of septimal meantone.
Chords of septimal meantone
Septimal meantone of course has major and minor triads, and also diminished triads, which come in both an
11-limit meantone
Septimal meantone can be extended to the 11 limit, but not uniquely. It is possible to take the interval of 11 by means of 18 fifths up and 7 octaves down, so that an 11:4 is made up of nine tones (e.g. C–E
Footnotes
References
External links
- "Composing in meantone". Xenharmony. Archived from the original on 1 April 2007.
- Terpstra, Siemen. "Towards a theory of meantone (and 31 ET) harmony". Stichting Huygens-Fokker (huygens-fokker.org).