Tonight was the final night of the second (and final) weekend of the Desert Trip festival, which was headlined by some of the most famous classic rock acts that are still alive and breathing. The festival, whose lineup includes Bob Dylan, The Rolling Stones, and Paul McCartney, shares a venue with Coachella and was also started by the same company, thus earning the nickname "Oldchella." McCartney returned to the stage last night for his second straight Saturday night set, and his performance included a surprise appearance from Rihanna, who joined him for their collaborative single "FourFiveSeconds," released in January 2015. Kanye West, the song's third collaborator, didn't show up, so his vocals were handled by Sir Paul.