If a prosaic movie can be redeemed, partially, by an excellent performance, then “I Saw the Light” and Tom Hiddleston's Hank Williams serve as point A and point B, respectively.

The good and the phony in the new Williams biopic sit side by side in the opening minutes. After the first of several faux black-and-white interview sequences featuring Bradley Whitford as Williams' producer, Fred Rose, aka “Mr. Exposition,” we get to the star. On a soundstage of the mind, swathed in highly theatrical lighting, Hiddleston performs an a cappella version of “Cold, Cold Heart.”

It's arresting. A hit for both Williams and, on the pop charts the same year, 1951, for Tony Bennett, the song is deathless, a lonesome killer for the ages. Hiddleston, a mellifluous, classically trained British actor best known to American audiences as Loki in “The Avengers” universe, clearly has done his research, his singing homework and his dialect lessons. He strikes a series of precise, Bob Fosse-gone-country poses accompanied by subtly shifting lighting cues.

But was Williams, who died New Year's Day 1953, after 29 years of hard drinking and bad behavior, this sort of performer? Hiddleston holds your attention from the start, but this dreamlike prologue doesn't feel quite right for the subject. The cockiness was there, for sure, and you can see it in the clips of Williams' early-television performances all over YouTube. But there's something off with the filmmaking from the beginning of “I Saw the Light.” For many, Hiddleston will be enough; for two hours, though, he and his co-stars struggle inside the cautious, clip-cloppy rhythm and uncertain style.

Writer-director Marc Abraham adapted his script from “Hank Williams: The Biography” and focuses on Williams' tumultuous love life, beginning with his first wife, fledgling and not-good singer Audrey, played by Elizabeth Olsen. “I Saw the Light” gets going chronologically in the year 1944, when Hank and Audrey got hitched in an Alabama filling station. Already the singer-songwriter's drinking was trouble, and it got worse. The movie tones down the physical abuse and plays up the roguish charm.

We see the Grand Ole Opry successes, the infidelities, the betrayals in due course. Abraham has the best luck with the early scenes between Hiddleston and Olsen; the actors suggest the tensions in the marriage subtly and well. But the writing is prosaic throughout, and longtime producer Abraham's second directorial feature suggests he has much to learn about activating a story visually. Even when it's sticking to the facts on the record, “I Saw the Light” makes real drama out of its real-life dramas only sporadically.

Hiddleston, his eyes full of fire and melancholy longing, was an inspired choice. Everything not quite right with most movies, however, goes wrong long before the actors arrive on set.

Michael Phillips is a Tribune Newspapers critic.

mjphillips@tribpub.com

Twitter @phillipstribune