ALRIGHTY!
So, I've been searching around, and here's what I found:
4 servers out of like 300 had radio that worked. about 10 said they did, but it didn't work. Some had a retard babbling down the mic at everyone, and when told to shut up, he claimed he is this hours DJ, and cannot be quiet for the next hour. I left.
Anyway, the 3 ways in which the 4 servers did it:
1) 4 of them had a connection to
Gamer FM This worked well, and played good music, and gave advertisements for their clans, and other clans who use them. Big possibility.
2) Custom mod with a DJ that takes requests and presents the show, and there was just an automatic playing thing which took over when no one was on, but quite often it would break and just play fuzz.
3) A demented child yelling down the mic occasionally playing 'BOOM HEADSHOT' and calling people hackers.