Do you ever feel frustrated that you're bussing tables when what you really want to do (and what you're really good at) is perform full-time? It's easy to lose hope when it seems like you're wasting time working at a dead-end day job. But have no fear! Some of today's biggest stars in music also had to work crappy jobs before their music gained any traction. Check out the not-so-glamorous day jobs that these nine famous musicians used to have.