Bosch is actually named after the painter. They call him Harry for short. I’ve read all the books. For once I’ve read books that you haven’t??? The books are by Michael Connelly who is also responsible for The Lincoln Lawyer. Mickey is Harry’s half brother and they intersect a bit in the books. Anyway, I think the opening credit music is a play on his extreme love of Jazz music. It plays heavily in the books and to a lesser degree on the show. It’s definitely a great tune.