I ran across this insightful interview with Music Supervisor Lindsay Wolfington from the show One Tree Hill. In it she offers the "other side" perspective of what they go through to get music into a show. Below were some key parts of the interview that stood out to me, with extra special emphasis added with italics:
A lot of people think it's simple to get music for a television show, but on the real side, what kind of process do you go through to get songs played?
LW: Music supervision includes much more than just picking songs that you like. Here are the essential steps: