"Twenty Feet From Stardom," about the back-up singers whose voices are familiar but whose faces and names are barely known, won the best documentary feature Oscar on Sunday. Darlene Love, one of those featured in the movie by director Morgan Neville, used the filmmakers' moment at the podium to blast out a rousing song, which had some in the audience up on their feet. Other back-up singers featured in the film, most of them African American, include Lisa Fischer, Tata Vega, Claudia Lennear, and Merry Clayton, the female voice on the Rolling Stones' "Gimme Shelter." The movie also follows a younger generation of back-up singers through Judith Hill, whose velvet voice entranced the "King of Pop" himself, Michael Jackson. She was supposed to be the main back-up singer on his doomed London mega-show "This is It," for which he was rehearsing when he died in 2009, ending her prospects of global exposure.