Ever see a movie or TV show where music is like one of the characters? Ever thought to yourself how cool it would be to be the one who actually chooses that music? Well, music supervisors are just that cool. Now, mind you, with that kind of coolness comes great responsibility (read: stress). After all, being a music supervisor isn't all about, "wouldn't it be awesome to have The Jesus and Mary Chain Just Like Honey kick in as Bill Murray rides through early morning Tokyo?" (Waiting for Translation - wow, is the music good in Sofia Coppola films) - in fact, that pay off of the perfect scene usually comes well after plenty of back and forth and negotiation between plenty of different parties with divergent interests.
In other words, music supervisors have to know their music, their licensing rules and their good negotiation strategies. But yeah, you're right - it is still a cool job (and no, it's not always about movies). Find out more about music supervisors work and see if it might be the perfect music industry fit for you.