Looking for references to the influence of Aleister Crowley, Thelema and Magick on the musical landscape of western culture can be like a trip down the proverbial rabbit hole.
If you are looking for something written by musicians and magicians about the intersection of their craft, here is a place where it is presented in their own words.
The Arcana series, edited by John Zorn currently boasts seven volumes and presents a treasure trove of information and insight. Currently featuring seven volumes published between 2000 and 2014, volume V focuses on the magical aspects of music and features contributions from William Breeze, Gavin Bryars, Alvin Curran, Fred Frith, Sharon Gannon, Larkin Grimm, William Kiesel, Yusef Lateef, Frank London, Meredith Monk, Mark Nauseef, Pauline Oliveros, Genesis P-Orridge, Terry Riley, David Toop, Greg Wall, Peter Lamborn Wilson and Z’ev.