Septimal quarter tone
A septimal quarter tone (in music) is an interval with the ratio of 36:35 (
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Composer Ben Johnston uses a small seven ("
The septimal quarter tone is tempered out by twelve-tone equal temperament, but not in any of 19-TET, 22-TET, 24-TET, or 31-TET. 22-TET and 24-TET offer a very close match to the septimal quarter tone.
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The septimal quarter tone is the difference between the 9:5 just minor seventh and the harmonic seventh.
References
- Douglas Keislar; Easley Blackwood; John Eaton; Lou Harrison; Ben Johnston; Joel Mandelbaum; William Schottstaedt. p.193. "Six American Composers on Nonstandard Tunnings", Perspectives of New Music, Vol. 29, No. 1. (Winter, 1991), pp. 176-211.
- "Ben Johnston's Extended Just Intonation- A Guide for Interpreters", John Fonville, p.113, Perspectives of New Music, Vol. 29, No. 2 (Summer, 1991), pp. 106-137.