Black Sabbath's Ozzy and Geezer Jam With Metallica

The big surprise came midway through the show when Metallica brought out Black Sabbath bassist Geezer Butler; Robert Trujillo introduced Geezer as "My hero, Cliff Burton's hero, Jason Newsted's hero," before they ripped through a mini-medley of "Sabbra Cadabra" and "A National Acrobat."