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.

The two had a jam sesh that included some Nirvana and Tom Petty, because we all know that Mayer has a dreamy cover of "Free Fallin'." They also pulled off an acoustic version of "Come As You Are" as the hyped-up audience took lead vocals.

Watch the clips and then read below for a story about Chappelle's hangout with Prince.