The EDM crowd is exactly the type of people I'd see targeting with this. As you suggested clubs could have their own "rooms", as well as individual DJs. Streaming live (if possible), and saving to an archive. Fans/listeners could obviously mark as favorite and get notifications when live or a new set has been uploaded from the club/DJ. Real time chat for discussion and requests. Frontpage with featured up and coming DJs, the most favorited and so forth.

As you remarked though, proper execution and probably contacts so as to get some sizeable DJs in from the start would be key for this to work.