U2 played the first U.S. date of their Joshua Tree anniversary tour in Seattle on May 14, and were joined by Pearl Jam frontman Eddie Vedder and Mumford and Sons for a set-closing rendition of the Tree track "Mothers of the Disappeared."

The moment, which you can catch via fan-shot footage above, started when U2 frontman Bono called out into the crowd for Vedder prior to the song starting. "Where's Eddie Vedder?" he shouted. "Spirit of Seattle!"

Thus beckoned, Vedder appeared on stage, helping lead the group through the final song on the LP's original track listing — and he was joined by the members of Mumford and Sons, who made their way back out after serving as the night's opening act. As the Oregonian noted, Vedder's appearance marked a bit of a full circle moment for Vedder, who spent time on the road with U2 when Pearl Jam opened for the band on its 1993 Zooropa Tour, and who'd been a fan long before meeting them in person.

"U2 was one of my favorite bands of all time," Vedder's quoted as saying in the Pearl Jam 20 retrospective book. "By the time of The Joshua Tree, they were taking the opportunity to push the stadium rock 'n' roll experience to another level, and they felt that was their duty, whether it was going to work or not."

The Joshua Tree tour, which celebrates the album's 30th anniversary and arrives alongside a freshly expanded edition of the watershed LP, started May 13 in Vancouver and is set to continue through late summer. For more on what to expect from the band's current shows, check out our coverage of the opening night performance, including photos, videos and set list.

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