The choice of music played by the DJs at the competitions is essentially left up to them. I'm pretty sure these people aren't a part of FIRST and are hired locally at the competitions, as are the entertainers at the Team Parties. (This is sort of evidenced by the different music played at the competitions - while KSC this year was mostly pop and more mellow rock, SBPLI the last two years has been more uptempo drum 'n bass, techno, and alt rock.)
So you're not going to get the same types of music at every competition, and there's of course no way you're going to please everyone at any competition. I much preferred the music at Long Island's regional, but other people (like my mom, for instance) perferred the downbeat music in Florida.
As for any choice vocabulary, yeah, FIRST probably gives the DJs guidelines, but how strictly they follow them is up for debate. (Remember the music video last year at Nats before the lazer show?
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