Very few voices qualify as national treasures. Mavis Staples' glorious rasp is one of them. Coming off critical acclaim for her 2007 collection of civil rights-era songs, "We'll Never Turn Back," and a 2008 live album, Staples joins forces here with Wilco frontman and fan Jeff Tweedy. The venerable singer revisits the soundtrack of her life, interpreting a mix of traditional gospel numbers harking back to her childhood roots as a member of the celebrated Staples Singers. (She also includes two Tweedy compositions.) Opening the set is the exuberant spiritual "Don't Knock," one of two songs written by her father, Pops. Staples' quiet reading of the Tweedy-penned title track resonates with subtle power, a talent the singer puts to good use on other songs written by Allen Toussaint, John Fogerty and Little Milton. The standout is Staples' tear-stained take of Randy Newman's "Losing You." She wrings every bit of emotion out of the song without seemingly batting an eye. At 71, Staples still knows how to hang tough and shows no signs of slowing down.