What happens when one of the world?s biggest music stars is unable to play at a major charity gig? He asks his famous mates to step in.
U2 front man Bono was due to perform with his band at the World Aids Day RED Concert but sadly he is still recovering from a recent accident.
But luckily Bruce Springsteen and Coldplay?s Chris Martin stepped in.
The two rock legends joined the rest of U2 on stage to perform with the band at the charity gig held in New Yorks Times Square.
The Boss, Bruce Springsteen rocked out before Chris stepped in wearing a rather fitting Substitu2 shirt
Also hitting the stage to raise awareness for AIDS was rap star Kanye West who treated the crowd to a medley of some of his greatest hits.
And Carrie Underwood who belted her tunes for the grateful audience.