VIDEO : Paul McCartney & Neil Young Share the Stage in Desert Trip Music Festival

Paul McCartney and Neil Young shared the bill at the Desert Trip music festival Saturday, and they also shared the stage during McCartney's set. Young joined the former Beatle to perform "A Day in the Life," which morphed into John Lennon's "Give Peace a Chance." The audience flashed peace signs as they sang along. Young played lead guitar to duet with McCartney on "Why Don't We Do It In the Road?" "Thank you, Neil," McCartney, 74, said when his friend left the stage.