Watch Twenty One Pilots cover Oasis with Post Malone at UK’s Leeds festival

ABC/Image Group LATwenty One Pilots recruited an unexpected collaborator during their set at the U.K.'s Leeds festival Sunday.

Post Malone joined the "Stressed Out" duo on stage in the middle of the concert to perform a cover of the Oasis classic "Don't Look Back in Anger." For their rendition, TOP frontman Tyler Joseph and Posty played piano and acoustic guitar, respectively, and traded verses before harmonizing for the chorus.

While that was happening in Leeds, Foo Fighters were headlining its partner festival, Reading, where they pitched an idea for a petition to convince Oasis to reunite. So if the combined powers of Twenty One Posty can't convince the estranged Gallagher brothers to reconcile, perhaps Dave Grohl and company can.

Twenty One Pilots will be back in the U.S. this fall for a headlining tour in continued support of their new album, Trench. The outing launches October 9 in Tampa, Florida.

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