Singer Mary J. Blige arrives at the 69th Annual Golden Globe Awards held at the Beverly Hilton Hotel on Jan. 15, 2012 in Beverly Hills

*The Associated Press is reporting that Mary J. Blige will write a song for a new documentary focusing on sexual assault in the U.S. military.

The R&B singer was at the Sundance Film Festival Friday for the premiere of “The Invisible War,” in which her song “Need Someone” already is heard over the closing credits. Producer Amy Ziering said that Blige, 41, would contribute an original song for the movie, which looks at the experiences of men and women who are attacked by their military colleagues and the difficulty of prosecuting such crimes. [Scroll down to watch the film’s Sundance trailer.]

The song will follow up her original ditty for DreamWorks’ “The Help,” which features her singing “The Living Proof,” a Golden Globe nominee this year for best original song.