Tom Hiddleston transforms into Hank Williams for film

When casting his Hank Williams biopic “I Saw the Light” (out Friday in Nashville, New York and Los Angeles, with a nationwide release slated for April 1), writer and director Marc Abraham found his leading man across the pond.

Playing Williams — a music legend dubbed the Hillbilly Shakespeare for the plainspoken pathos of compositions such as “Your Cheatin' Heart,” “Men with Broken Hearts” and “I Can’t Help It If I’m Still in Love with You”— is London-born Tom Hiddleston, a Royal Academy of Dramatic Art alum who got his start on the stage in Shakespeare works such as “Othello” and “Cymbeline.”

None of his previous roles prepared Hiddleston, best known for his turn as the villain Loki in "The Avengers," to play Williams, one of the pillars of 20th-century music.

“I’ve never worked harder on anything in my life,” he said. “I needed to look like Hank, to sound like Hank, and to represent his struggles and celebrate his talent, but ... I needed someone to show me the way.”

The film's executive music producer, singer-songwriter Rodney Crowell, took on that task as Hiddleston's country music coach.

"Tom did not show up like 'I'm an actor, I've got this,' " Crowell said. "Who showed up was an artist who said, 'I have nothing but the utmost respect for Hank Williams, and this is a very serious undertaking. I want to give it my all. I want it to be as true and authentic as it can be. What can we do?' "

The actor stayed with Crowell in Nashville for five weeks and immersed himself in all things Hank, learning how to mimic his vocal inflections by studying his studio recordings as well as the Mother's Best radio shows Williams taped with his backing band, The Drifting Cowboys, in 1951.

“I knew that was the only way I had to do it. I had to take myself out of my comfort zone, away from London … not being around actors or film people, but being around musicians (and) getting into the soul of country music and Nashville and the South," Hiddleston said.

He and Crowell had long conversations about the music and history of the American South during the time when Williams was a gangly kid growing up in Alabama, and how that influenced the music he recorded.

"(Hank's) joy as a performer is something I related to, but he also had this deep well of sadness and remorse and anguish," Hiddleston says. "The contradiction within him is what makes him so fascinating."

Songwriter says he talked to Hank Williams' ghost

Born in 1923 with spina bifida, Williams was plagued with back pain throughout his adult life and struggled with addiction — which got him kicked off the Grand Ole Opry in 1952, just three years after his debut on the show, where his rendition of Cliff Friend and Irving Mills' "Lovesick Blues" got an unprecedented six encores. He died in the back seat of a Cadillac on New Year’s Day 1953 while on the way to play a show in Ohio. He was 29 years old. He left behind a potent body of work, and the songs he penned, such as "Move It On Over" and "I'm So Lonesome I Could Cry," are some of country music's most beloved classics.

It's serious subject matter, but while talking about their preparations for the movie, Crowell and Hiddleston snicker like schoolboys playing hooky.

“We were just giggling our way through a day’s work,” laughs Crowell. “It was hard work, but joyful.”

The effort Hiddleston and Crowell put into their mission is obvious throughout the film. While “I Saw the Light” is a clunky and unfocused march through the last years of Williams' life, Hiddleston's performance is magnetic. He and co-star Elizabeth Olsen, who plays Williams' first wife, Audrey, make a charismatic, occasionally volatile pair.

Although it's been more than a year since Hiddleston transformed himself into Williams, and he's filmed multiple projects since then, the experience of becoming the Hillbilly Shakespeare is something he'll never forget.

“Playing Hank Williams is one of the great privileges of my working life," he says. "It’s funny, I feel like I know him. I feel like I’ll always know him now.”

I Saw the Light (Sony Pictures Classics)

123 minutes

Rated R

The film opens exclusively at Regal Green Hills on Friday. Additional theaters will be added April 1.