Keith Urban and John Mayer will be teaming up for an episode of CMT's Crossroads for an invitation only crowd tomorrow night in Nashville. This will be Urban's second time being involved with Crossroads. His first appearance was with Rock and Roll Hall of Famer John Fogerty who was a part of the '60s and '70s band Creedence Clearwater Revival. Mayer has also been on the show before with Brad Paisley. No air date has been announced for Keith and John's pairing.