"What are you doing here?" Replacements leader Paul Westerberg had just sat on a couch onstage with his guitar, three songs into the band's second-weekend set, and now he was looking up at Green Day's Billie Joe Armstrong, suddenly standing beside him, bearded and scruffy, and dressed in a ridiculous suit of Replacements plaid. Armstrong was ready to play with the band, declaring into the mic, "Sometimes dreams do come true."
Armstrong is a longtime fan of the Replacements, whose songs of melody, chaos and real vulnerability were a key influence on Green Day's music. And he dove into the panicked "I'm In Trouble" like the 'Mats devotee that he is, followed up by the urgent and yearning "Kiss Me On The Bus" and "Aching to Be." He slashed at his guitar, figuring out the songs as he went, and traded vocals with Westerberg, who reclined happily on the couch.
Westerberg explained that back trouble had led to Armstrong joining the band unannounced, and the Green Day leader remained for the whole set. "Billie, you'll fall right into it," joked bassist Tommy Stinson. "It's in E, like all the others."
Westerberg rose from the couch for the set-closing songs "Left of the Dial" and "Alex Chilton," both tributes to the making and sharing of music of real purpose and personal meaning, and shared a mic with Armstrong. The band then returned for a rare Coachella encore with "Can't Hardly Wait," and Armstrong waved his goodbyes.