Watch Bruce Springsteen join Zach Bryan onstage in Brooklyn

Paul Bergen/ANP/AFP via Getty Images; Michael Buckner/Variety via Getty Images

Jack Brian has never hidden his deep love for Bruce Springsteen, so there's no reason to think he was sending a hidden message when he used „Johnny 99” as his walk-on music at Barclays Center in Brooklyn on Wednesday night. Springsteen took the stage in a tour T-shirt with the sleeves cut off. But when Bryan began his two-song encore with a rendition of his as-yet-unreleased song „Sandpaper,” Springsteen strolled onstage without warning.

As the stunned crowd cheered, the two men traded lines on the song's verses and Springsteen took the high parts, singing („For 27 seasons now they've been trying to soften me up”). From there, Bryan kicked off his usual show-closer, a barnstorming „Revival,” and Springsteen stayed onstage, where he was joined by Maggie Rogers, who had duetted with Bryan on „Dance” earlier in the show.

Bryan usually introduces his band during „Revival,” and he added an extra member Wednesday night: „His name is….Springsteen!” Springsteen sang on and off the mic with Bryan's band „Revival,” at times sharing one with a visibly ecstatic, tambourine-toting Rogers. Springsteen played a short but glowing guitar solo and joined the rest of the players for some dance moves.

Springsteen's appearance was a major performance honoring the younger artist. In the middle of a series of shows with the E Street Band on the West Coast, Springsteen flew east to play with Bryan, learning to „sandpaper” the day of the show, according to a source familiar with concert logistics. Springsteen had to return to California immediately to perform in San Francisco on Thursday evening.

Elsewhere in the show, Bryan played as-yet-unreleased songs („The Great American Bar Scene” and „Better Days”) from a new album he says is coming later this year, amid a crowd that roared awestruck through his hits.