Watch John Mayer & Dave Chappelle Jam to Nirvana

Watch John Mayer & Dave Chappelle Jam to Nirvana

John Mayer and Dave Chappelle are old buds (Mayer's cameo on The Chappelle Show will forever be the funniest), so when the guitarist hopped onstage at Los Angeles' Hotel Cafe on Wednesday for a secret gig, he surprised everyone with Chappelle.