Stars Julia Roberts, Joan Baez, Little Mix join Taylor Swift's squad

After last night’s 1989 World Tour stop, Taylor Swift officially has six new additions to her squad. Taylor Swift invited the members of Little Mix on stage at her show in Santa Clara on Saturday, joining them in a performance of their hit “Black Magic.” “They smashed it tonight in front of 50,000 screaming fans,” Swift wrote on Twitter after the show. “Amazing.” “ OMG cannot quite believe what's just happened, one of the best experiences in our little mix life ever! Cannot thank @taylorswift enough for having us tonight, 60,000 incredible screaming swifties with a sprinkle of Black Magic, thank you for being so welcoming to us! We love you Taylor can't wait to catch up very soon! xx Little Mix xx," Little Mix tweeted afterwards. But the members of Little Mix weren’t the only surprise guest at Swift’s Santa Clara stop: Joan Baez and Julia Roberts also appeared onstage, where they “danced it out to ‘Style,’” Swift tweeted. “These two women are my heroes. What an honor.” So far, everyone from Fetty Wap to the U.S. Women’s National Soccer Team have joined Swift on stage. TIME