http://dswarmsikhttkg7jgsoyfiqpj3ighupfrvuz5ri3lu5q2dlqyrpgk7ad.onion/share/archive/misc/zender.A_Roadmap_for_Orpheus.html
The divergence of the fifth harmonic, 14 cents,
(with a tolerance of 2 to 3 cents, or the amount that allows us to
experience differences of fifths in an equally tempered system as ’still
pure intervals’) is half that of 33 cents, and thus a twelfth of a tone.