A measure of the dissonance due to the size of the prime factors of musical intervals (Barlow, 1987).
The indigestibility, x(P), of the prime number P is defined as 2*(P-1)2/P. Examples are x(3) = 2.667, x(5) = 6.400, and x(7) = 10.286.
The indigestibility of a composite number is the sum of the indigestibilities of its prime factors. For example x(15) = x(3) + x(5) or 2.667 + 6.400 = 9.067.
Indigestibilities are combined to generate the harmonicity and specific harmonicity functions
Hi Joe,
You probably missed my remark that indigestibility isn't meant as a measure of dissonance by Barlow.
So I think you should change this page. Rather, it serves as a measure of divisibility for the harmonicity function, which is a measure of harmonic cohesion.
So harmonicity isn't a measure of dissonance either, but your page doesn't say that.
Best,
Manuel
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