Natalie Maines is supporting the West Memphis Three with a cover of Pink Floyd's 'Mother' for 'West of Memphis: Voices For Justice,' a benefit album for Damien Echols, Jessie Misskelley Jr. and Jason Baldwin, whose story is told in the 2012 'West of Memphis' documentary. The longtime Dixie Chicks singer's performance only hints at her country pedigree, and leaves behind much of the bravado she's known for. It's a humble, passionate cover.

Roger Waters left a lot of room between lyrics in his original 1979 track from 'The Wall.' That's dangerous for someone approaching the song anew. There's space to improvise, which would generally not be a good idea. Maines respects the original arrangement, allowing only her natural vocal style to alter the song from the one classic rock fans know and love.

"Ooooh Babe Ooooh Babe Ooooh Babe/ Of course Mama's gonna help build the wall," she sings. It's a personal performance and one could theorize that the fact that she's an actual mother figures into her attachment to the story. There's not an inch of familial pathos however as she sings:

"Baby don't you cry / Mama's gonna check out all your girlfriends for you / Mama won't let anyone dirty get through / Mama's gonna wait up till you get in / Mama will always find out where you've been."

There are points in the song for the controversial singer to politicize, but she avoids bringing unnecessary attention to these moments. At about three minutes, one feels the presence of a country guitar and organ, but it's only an accent or a garnish to a rendition that stays remarkably true to the Pink Floyd original. Yet in the context of this film and the real-life events that inspired it her vocals carry new weight. Maines' 'Mother' is much more bittersweet in this package.

Listen to Natalie Maines' recording of 'Mother' at NPR.org.