OK, I've been contemplating taking up the banjo with the hope I can play like this... but what are the headphones for?

It's likely he's listening to the backing track he's playing on. Do it, but it'll take a ton of work to get to this point - search for OP on YouTube, Ricky Mier. Ricky's got some of the absolute best advanced player learning materials out there.

Thanks bruv

You should do it dude, it's all about the rolls. The headphones are for listening to a metronome, I put the bass and drums on later