As an artist-fan, you could just have a conversation based on the world as you see it and as he sees it; many topics of interest can be had if they relate to periods in his own writing and what inspired him. If you are also into making music, there would be a natural conversation built right in-influences, other musicians you both admire.
Keep it on a personal level, versus a fan-worshipping level; many pros get ‘weirded out’ by that kind of conversation. Also if you’re a musician, you can ask for pointers and tricks “of the trade” that can help out your own musicality. If you’re not a musician, maybe bringing up other art forms you admire and relating of things that inspire you in art and music, may be some good directions. If you’re lucky, he could share some ‘war stories’ from his touring days-musicians love to talk about that kind of stuff.
Just be yourself; relax and go into the meeting as if you’re long-time friends; your familiarity with his music can be the basis for that, just don’t let it steer the conversation.