Some of Oscar's most memorable moments have come during performances of nominated songs. Among them: rap group Three 6 Mafia surrounded by streetwalkers as they performed “It's Hard Out Here for a Pimp” from “Hustle and Flow” in 2006, and Celine Dion's resplendent performance of the “Titanic” hit, “My Heart Will Go On,” in 1998. Don't expect such musical moments at the 82nd Academy Awards. The artists behind the year's five nominated songs will not perform during the Oscar telecast. Instead, the songs will be showcased with clips from the films that featured them, “which is how most nominated achievements are featured within the show,” Academy of Motion Picture Arts and Sciences spokeswoman Leslie Unger said Wednesday.