Geezer Butler made a surprise appearance at Tom Morello's Power To The People All-Dayer on Saturday at the Merriweather Post Pavilion in Columbia, Maryland.
The all-star show, which featured appearances from Cypress Hill, The Linda Lindas, Killer Mike, Nathaniel Rateliff, Matt Cameron, Public Enemy, Dave Matthews, Joan Baez, Dropkick Murphys, Stephen Stills, Foo Fighters, Bruce Springsteen and Morello himself, also included a three-song set from Jack Black – who wore an Ozzy Osbourne-style fringed jacket for the occasion.
After performing Ozzy's Mr Crowley and Black Sabbath's The Wizard, Black was joined onstage by Sabbath bassist Geezer Butler for a rousing cover of Sabbath's War Pigs.
Other stars appearing onstage at the Merriweather Post Pavilion included the Pretty Reckless's Taylor Momsen, Pearl Jam's Mike McCready and bassist Robbie Mangano, who joined Morello onstage during Matt Cameron's "Sons of Soundgarden" set.
Meanwhile, Morello's set featured appearances from System Of A Down frontman Serj Tankian, Public Enemy's Chuck D, Run DMC's DMC, Anthrax's Scott Ian, Jack Black and Dave Grohl, who sang on a closing cover of Kiss's Rock and Roll All Nite.
"The Power to the People festival is about freedom, justice, equality and rock'n'roll," Morello said in a statement. "It’s about the power everyday human beings have when they come together through music, art, community, and action. We’re honoured to bring this incredible lineup to the DC area for a day that celebrates the spirit of activism, creativity, and hope."
