You’ve been dancing your whole life, so when it comes time to start auditioning for musicals, it’s not the dance portion you’re worried about. You can time step and piqué turn with the best of ’em. But at musical theater auditions, there’s new lingo to learn, and you can’t just show up with your tap shoes hoping for the best. What if you have to sing? What is an “audition book”? What are you supposed to do with sheet music?