Remember Desert Trip, the “Oldchella” music festival where Bob Dylan and Paul McCartney and Neil Young and the Rolling Stones all performed last weekend? Like Youngchella, it is actually two weekends long, and McCartney returned to the stage Saturday night. This time, he invited Rihanna to sing “FourFiveSeconds,” her 2015 single featuring McCartney and Kanye West. West was not in attendance, so McCartney took over his vocal part. Watch below.