A scale devised by Wendy Carlos, which does not have octaves, because of its equal "step size" of 63.8 ¢, with 18.809 steps per "octave".
It is "defined strictly as a local minimum of the root-mean-square error function that Wendy set up with 3/2, 5/4, 6/5, 7/4, and 11/8 as target intervals."
The Carlos Beta tuning splits a tempered "perfect-4th" into two equal parts, each of which in turn are twice divided in half - thus, the perfect-4th subtends 8 equal steps of 63.8 ¢ each. The first "8ve" of this scale is covered by the following notes in descending order:
degree cents 19 1212.2 18 1148.4 17 1084.6 16 1020.8 15 957 14 893.2 13 829.4 12 765.6 11 701.8 10 638 9 574.2 8 510.4 7 446.6 6 382.8 5 319 4 255.2 3 191.4 2 127.6 1 63.8 0 0Examples of its use can be found on the title track of her album Beauty In The Beast.
Various EDOs give approximations to the Carlos beta scale:
Used in its lower-case form β as an additional letter-name in Erv Wilson's notations, signifying a note near "B", but with a musical function separate from "B", in whatever particular scale the notation is describing. See The Wilson Archives for examples and explanations of his notation.
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