Mary J. Blige lends a reassuring voice on “The Living Proof,” the theme to the film The Help, in theaters now. The survivors’ anthem, produced by The Underdogs, was written about Aibileen (Viola Davis), the main character who plays a maid living in Mississippi during the 1960s. The video features footage of Mary in the studio interspersed with clips from the civil rights dramedy. Find your strength in the music.