While there aren't many field faults, they will play the traditional FIRST dances at times. There usually is a time-out used in the playoff matches, and then once you're in the finals everything's back-to-back anyway so they have a field timeout and have some time to kill.
I don't remember where I saw it originally (as I'm not involved with DJing in any way), but
http://firstmusicdjs.com/ has information and playlists for DJs to use at competitions. I have no idea how official that site is or if all events follow it exactly, but it should give you a good idea of what'll be played (or at least what was played last year).
I'm currently planning on volunteering at Nashua (though I haven't been confirmed for a specific role yet), so I'll see you there.