Paltrow's latest role as a faded country singer is a gamble for an actress known more for art-house fare. But her upcoming CMA awards spot and other high-profile moves are a step in the right direction for building credibility.

GUITAR MOM: Gwyneth Paltrow learned to strum a guitar as country singer and mom Kelly Canter. (Screen Gems)

This summer, programmers at Go Country 105 radio in Los Angeles unveiled a new single called "Country Strong" and asked listeners to guess who was the twangy alto belting out lines about how she's "hard to break, like the ground I grew up on."

Callers rang in, naming pop country divas such as Martina McBride and Faith Hill, but they were stumped. Perhaps that's because the ground this singer grew up on was Santa Monica and New York City — and about as a hard as a featherbed.

"Country Strong's" unlikely performer — and star of an upcoming movie of the same name — is Gwyneth Paltrow, one of Hollywood's most citified actresses. The drama, coming to theaters in December, is a major departure for a woman known for her art-house pedigree, Grace Kelly looks and marriage to Coldplay rocker Chris Martin.

To play faded country star Kelly Canter, Paltrow had to learn to strum a guitar, sing in stadiums full of extras, and drawl like a Southerner (despite now living in London). On Wednesday, the actress is taking a nervy step at earning some country cred: She'll perform live on national TV on the Country Music Assn. Awards, with one of the genre's most respected singers, Vince Gill.

"Most people, they start in a bar, and then a little bigger bar. You're not supposed to start at the CMAs," Paltrow told Chicago country station US 99.5 in October, in one of the few interviews she has granted about "Country Strong." "If I don't faint, if I just get through it, it'll be OK."

The CMA performance, though, is hardly an attempt to launch an enduring country music career for the actress — it's a bid to promote the movie and demonstrate the country music establishment's endorsement of the project. But pitching Paltrow so visibly and so far ahead of the film's release is risky: If country fans embrace her, they'll be primed to support the film. If they see her as a Hollywood opportunist, "Country Strong" could be doomed with its target audience before it even hits theaters.

"It's an exceptionally clever strategy because you want to overcome any negativity people have about seeing her in that role," said Mark Young, a professor at USC's Marshall School of Business. "Lots of people are wondering, 'Can she sing? What's the deal?' Well, she actually sings pretty well. If you waited and just released the film without letting audiences hear her, people might just stay home."

Paltrow has sung on screen before. She paired with Huey Lewis in "Duets," a 2000 karaoke movie directed by her father, Bruce Paltrow, and she played a Peggy Lee-esque lounge singer in the 2006Truman Capote biopic "Infamous." Next week, she'll guest star as a substitute teacher on "Glee," delivering renditions of "Singing in the Rain," Rihanna's "Umbrella" and a PG-rated version of an expletive-filled Cee-Lo Green song.

Other mainstream actors have delivered credible performances as country stars — for instance, Reese Witherspoon in "Walk the Line" and Jeff Bridges in "Crazy Heart." Paltrow's to-the-manner-born image, though, makes her an odd choice for a movie set in the blue-collar world of country music. When she croons about a double-wide in the movie's ballad, "Coming Home," it's hard not to picture a star trailer on a studio lot.

"Country Strong" writer-director Shana Feste said the chance to pivot professionally was a large part of why the role appealed to Paltrow. "A lot of people associate her with being British, urban," Feste said. "It was so out of her wheelhouse. She knew this would not be an easy role."

Paltrow was drawn to the character's grittier aspects — she drinks, takes drugs, cheats and slaps her husband, played by Tim McGraw. "It's a dark role with a lot of unlikable moments," Feste said. "When you whack Tim McGraw, there's a lot of women you're making mad."

Paltrow's best-known movie performances are as Pepper Potts, Tony Stark's faithful Girl Friday from the "Iron Man" films, and her Oscar-winning turn in 1998's "Shakespeare in Love." Since the birth of her first child in 2004, Paltrow, now 38, has had leading roles in only two small films — one directed by her brother, Jake, and the other in the Joaquin Phoenix romance "Two Lovers." Lately, it's her off-screen life that seems to get the most attention — including her friendships with celebrities like Madonna, children named after fruit (Apple) and a prophet (Moses) and a quirky lifestyle blog, Goop, which covers such rarified topics as Parisian hotels, organic fashion and colon cleanses.

Mindful that her casting could be seen as a gimmick, the filmmakers paired Paltrow with established Nashville artists, songwriters and producers. Her recordings for the movie were produced by Byron Gallimore, the Music City veteran who guided many of the biggest hits by McGraw's wife, Faith Hill. The band that backs Paltrow in the film includes admired singers and songwriters Patty Griffin and Jim Lauderdale. In addition to Hill, Hank Williams Jr., Lee Ann Womack, Trace Adkins and Ronnie Dunn (of Brooks and Dunn) appear on the soundtrack.

"Once we lined up our murderer's row of producers, that was a sign to the country community that we had good intentions and good taste," said Randall Poster, the film's music supervisor. The actress also got an assist from her husband, who penned a song on the soundtrack she sings with McGraw called "Me and Tennessee."

When filming started in Nashville in early 2010, Hill and McGraw helped Paltrow find her inner cowgirl. The actress (a one-time vegan) sampled the fried chicken at a spot called Swett's, saw Lauderdale play the bluegrass venue the Station Inn and took in shows by Gill and Emmylou Harris at the storied Ryman Auditorium.

For film marketers, "Country Strong" hits a lot of the right demographic notes. Paltrow, and to a greater extent McGraw, are likely to appeal to the adult women who constitute the majority of country music consumers. McGraw — who does not sing in the movie — is building on the acting career he launched with "Friday Night Lights" in 2004 and continued with roles in "Flicka" and "The Blind Side"with Sandra Bullock. Rounding out the cast are Leighton Meester of "Gossip Girl" and Garrett Hedlund, who will also be seen in December's "Tron: Legacy."

Country fans, and award show producers, often embrace celebrities from other fields: Matthew McConaughey was an award presenter at the last two Academy of Country Music Awards shows, and the ACMs last year also included Jamie Foxx in a guest role in which he proclaimed his love for country music. Former Hootie and the Blowfish leader Darius Rucker has carved out a new career as a singer and writer of country material, and Sheryl Crow and Kid Rock have dabbled in the genre.

But country radio programmers could still sink Paltrow's bid for legitimacy because she seems to lack the potential for longevity.

"Gwyneth's already obviously a huge star," said Lon Helton, publisher of the country music and radio trade publication Country Aircheck and host of the nationally syndicated "Country Countdown" radio program. "From a radio programmer's perspective, every time I play that record, I might be not playing one by somebody else who could help me down the road. Is she going to have a country artist career? Is she going to put out records after this movie is over? That's a conundrum for them right now."

Label and movie executives expect Paltrow's appearance on the CMA show to bolster interest in the film. But if Go Country's experiment with listeners is any indication, Paltrow's best chance for acceptance may be if audiences listen first and learn who's singing later.

"When we told the audience 'That is actress Gwyneth Paltrow,' they said 'Great — play it more,' " said Go Country program director Tonya Campos, " 'She can sing.' "

rebecca.keegan@latimes.com