Hacking the Starbuck's Muzak Machine?

llamaluvr asks: "My friend is employed at a Starbucks coffeehouse, and he told me about a system they use for controlling what kind of music is played in the store. The machine can only play a particular type of CD, which contains 90-100 songs that "expire" after awhile, and is appearantly compiled/ produced by Hear Music, a subsidary of Starbucks. PlayNetwork is in charge of the the hardware. Anyway, he and his fellow employees are sick of Starbucks lame playlists, and they can't use normal CDs, as the machine tells them that the CDs are "expired". Does anybody know anything about how this system works? Is it at all possible to make a CD on your own that can be played on these machines?"