09/09/2009 at 05:15 PM EDT
will be singing and playing the guitar in an upcoming film, and she makes one guarantee about her big-screen musical debut
: "I can carry a tune."
Aniston is both starring in and producing The Goree Girls
– the story of a real-life 1940s-era country music group comprised of all-female prison inmates – and is currently honing her singing skills as the production prepares to roll in January.
"It won't be bad," Aniston says while promoting her latest film Love Happens
. "Here's the good news: the band – they weren't musicians. They basically created a band in prison in order to get paroled. So you're dealing with new singing voices and new instrument playing and somehow they find a way and become a huge phenomenon. It's a true story."
Aniston, 40, says it's not exactly her first time testing her pipes. "I think I sang one little thing in a movie a long, long time ago," she says.
And she had to attempt the occasional musical number while attending New York's High School of the Performing Arts, the school that inspired Fame
. "It actually was not bad. It passed, somehow."
Thinking back on her early days testing the acting waters, she remembers her father, actor John Aniston (best known as Days of Our Lives
' Victor Kiriakis), was not enthusiastic about her career plans.
"My dad did not want me to do this at all," Aniston says. "It wasn't that he didn't think I could, but he just thought that it was such an iffy thing ... I think there was a part of that [which] kind of fueled my drive in a way."