In the Spring of 1913, in Crowley's Equinox journal (Volume 1 #9), Aleister Crowley published a short article (now available separately) entitled Energized Enthusiasm. While actually focused on sex magick, there are concepts included that extend to all forms of magick.
Being a musician myself, I like that Crowley relates music and magick. He writes,
Music has two parts; tone or pitch, and rhythm. The latter quality associates it with the dance, and that part of dancing which is not rhythm is sex. Now that part of sex which is not a form of the dance, animal movement, is intoxication of the soul, which connects it with wine. Further identities will suggest themselves to the