Although many know me from my seven and a half years on air at MTV, I have always been and always will be a radio guy. Logs were paper based and patching a phonecall through often consisted of contortionist tricks even Nixon's secretary couldn't perform. The mp3 compression scheme enabled easy transfer of formerly large data files across even the narrowband Internet. Peer to Peer technologies like Napster, Gnutella, Freenet, Kazaa, Konspire etc etc. have forever ensured that the music is findable and retrievable. All you really need to do is perform one search query across all P2P file storage systems and you are presented with multiple options for downloading the desired song.
Separation is an issue at the playout system level.
Formats are the magical element in virtually every product or service, it is what mankind uses to differentiate them selves. McDonalds has a great fast food format, closely replicated by Burger King, but never quite the same, and judging from their burgers, they both provide similar content, but perhaps from different suppliers and in turn their burgers contain scriptable formats, differing in order, elements and texture. These two functions work closely together to determine the exact format of the station and what content they will fill the format with. These are just a few and new formats such as Alternative Rock and EDGE are appearing all the time. In essence all radio formats are based over time, typically in 60 minute increments in turn subdivided into quarter hours.