Dan,
The music industry is filled with cranks and religious eccentrics, or at least it was. These days it is filled with smelly, boring children looking for a pot of gold. A JW was not something terribly unusual. I know many JW's who are in the industry and have survived for years relatively intact. The secret is to to be able to dislocate your life and relocate it without struggling too hard with the diachotony. I was never one for the drug, party or groupie scene even before my induction into the WTS, so my behavior was not terribly different anyway.
To my shame I did interrupt the budding career of an excellent musician, a drummer as it so happens. He had cut three albums and was doing quite well. I studied with him and he became a JW. He gave up the sticks despite my trying hard to get him to see that he had no need to walk off the job. Last I heard he was a miserable as a diaebetic in a sugar refinery, trailing around the streets pushing a pram with a brace of kids as he goes from door to door. Needless to say, he returns my mail unanswered these days.
Best regards - HS