A rare and beautiful thing happened at Fenway Park Sunday night (Aug. 9), when legendary Aerosmith frontman and recent country star Steven Tyler joined Zac Brown Band onstage to perform some of Aerosmith’s greatest hits for unsuspecting fans.

Zac Brown Band launched into the iconic drum beat and guitar lick of “Walk This Way” as Tyler appeared on stage to an eruption of cheers. The eccentric singer slid right into the verse and showed off his vocal chops as the band jammed along with perfect accuracy and skill.

“We take it pretty seriously when we do a cover,” band member Jimmy De Martini says. “We get down note for note and add our own style, too. A lot of the jam bands we grew up with, like Phish and the [Grateful] Dead, they do a lot of covers. We now see, when you’re out there every night, how playing covers can feel new to us, and they’re recognized by the crowd.”

Brown joined in on the chorus with a lower harmony line, and the band looked like they were having a great time playing the classic. They also treated the audience to another Aerosmith mega-hit, “Sweet Emotion,” all singing harmonies together on the infamous chorus. Check out the video below to see the second performance.

Tyler, who waded into the country music realm with his latest single “Love Is Your Name,” has expressed his affinity for ZBB, saying they add an element of rock to the game.

“Country’s the new rock because of people like Zac who aren’t afraid to throw in a couple of good guitar licks,” Tyler tells USA Today. He’s even cited “Homegrown” as one of his favorite country songs.

Tyler’s appearance marked the last show of the three-night run at Fenway for ZBB, who are currently touring in support of their latest record, Jeckyll + Hyde, also a testament to the band’s versatility in style. The guys will be hitting D.C. and Philadelphia later this week, then on to New York state.

Watch Steven Tyler and Zac Brown Band Perform "Sweet Emotion"

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