Paul McCartney has spent the last two weekends in Indio, California, for Desert Trip, the classic rock festival thrown by the people who bring you Coachella. Crowds had a decent idea of what to expect given that the Beatle rolled through a ton of his career favorites last week, but they were totally floored when he threw a huge surprise into the mix: Rihanna.

"FourFive Seconds" was a part of Paul's first Desert Trip set, but for the second time around, he brought out Ri for the performance of their 2015 collaboration with Kanye West, and she sounded incredible.

Considering the crowd at Desert Trip — who definitely skew older, and thus favor Macca's greatest hits instead of his latest ones — they threw the lyrics of the song up there so that everyone interested could sing along. Not that she needed the help, as she belted the living daylights out of her part of the tune and succeeded in holding her own alongside one of the greatest rockers alive.

She definitely carried more than her own weight on the track, too: Kanye's taking a break from the Saint Pablo tour and didn't make an appearance at Desert Trip (and dude is absolutely excused given everything going on in his personal life).

Good to know Macca's still full of surprises — and even better to know that Rihanna can just show up in a pinstriped suit and get down to business like a boss, even if she's not even on the lineup.