But Abraham explained that the film — due in theaters starting on March 25 — is less of a "typical biopic," and more about the entertainment industry and "what it is to be an artist as a young man." He added, "It's not about following all this guy's greatest hits."

Adapting Colin Escott's Williams biography I Saw the Light for the screen came with risks that started long before that cold day spent shooting "Hey Good Lookin'." Simply securing the rights was "insane," then came the fact-checking for historical accuracy, and then the music itself, which Abraham insisted be performed live by his cast, as opposed to lip-synched or performed by a separate vocal artist.

"When I first talked to Tom, I said, 'One, you'll have to be able to sing the songs,'" Abraham remembered. "'And, two, you'll never sound exactly like Hank Williams.'"

Instead of attempting a carbon copy of Williams' songs, Abraham directed Hiddleston to approximate the "emotional impact" that the legendary singer inflected. The British actor has sung for other projects, and can play piano and guitar — plus, he's undergone plenty of physical transformations for roles, like Loki for the Marvel movies or Thomas Sharpe in Crimson Peak.