The actress will belt out a number or two as the star of The Goree Girls, in which she'll play a member of a real-life 1940s prison country group.
Director Michael Sucsy has yet to cast the other members of his band, but he's happy with his first choice, and plans to bring other non-professionals onboard.
He tells Eonline.com, "She (Aniston) can sing... These women learned to harmonise and they learned to play instruments. They weren't these amazing, accomplished singers who banded together. That's what's interesting about it.
"It's not just like, 'Hey, you can play the guitar, I can play the piano, I can play the harmonica. Let's put a band together.' It's like, 'We have to get out of jail, and if we have to put a band together to do that, then that's what we're going to do.'".