Happy Birthday, Gavin!

Sunday night at Carnegie Hall in New York City, U2, Courtney Love, Scarlett Johansson, Antony Hegarty, Rufus Wainwright, and surprise guests like Lou Reed and Lady Gaga came together to celebrate the 50th birthday of Gavin Friday, solo singer/songwriter, actor, painter, and onetime frontman of Irish band the Virgin Prunes. The event doubled as a fundraiser for (RED), a charity that helps fights AIDS in Africa.

During the three-hour concert each artist covered one of Friday's songs. "This is going to be one interesting night," Bono said, introducing Friday, a childhood pal who grew up on the same Dublin street. Gaga -- introduced by the U2 frontman as "at the top of the pop game" -- performed a brand new song written especially for the show.