New York ? It’s pure Hank Williams: that lonesome, desperate gaze, tinged with equal parts charm and chilling menace; that stoned stagger, that irresistible twinkle in the eye.

At least, that’s what Jason Petty has audiences believing in “Hank Williams: Lost Highway,” which recently moved to the Little Shubert Theatre for an open-ended run after winning rave reviews and selling out during a limited engagement at the much smaller, off-Broadway Manhattan Ensemble Theater.

The music is the life of the show, and Petty consistently nails Williams’ honky-tonk timbre with eerie authority.

“One thing I said to myself about this show was, if we mess everything else up but get the music right, people will still enjoy themselves,” says Petty.

Petty, a farm boy from Lookout Mountain, Tenn., has been singing most of Williams’ venerated canon since he performed as an impersonator at Nashville’s now-defunct Opryland in the mid-1990s. But his portrayal of Williams has come a long way from the days of hamming it up at the theme park, where he was first noticed and asked to audition for “Lost Highway.”

“I was just lucky that I had the look,” he says. “I’m tall and skinny and got the gaunt, long face — and the dark, beady eyes.”

That kind of aw-shucks modesty belies a man who, with precious little acting experience, not only has honed his singing to an uncanny perfection for the show, but went to great lengths in learning about a man whose legend is as slippery as his trademark cowboy yodel.

“As far as Hank’s off-microphone things, that totally has to come from you, and the things you’ve learned through your research,” says Petty, who visited Williams’ boyhood home, pored over rare scraps of film footage and talked with countless people who knew him and shared their tales, some of which have grown taller over time.

“People came out of the woodwork to tell me about Hank — members of his former band, the Drifting Cowboys — I got to go have dinner at their homes and listen to their personal audio tapes of live shows at county fairs that no one knew were even recorded,” he says. “But because there are so many stories about Hank’s life, it’s hard to separate the fact from fiction.”

‘A darker spin’

The outlines are well-known: He drank heavily and used drugs, in part to dull chronic and debilitating back pain, a mixture that killed him at age 29 of heart failure, sometime between New Year’s Eve 1952 and New Year’s Day 1953. His reckless, Saturday-night abandon always gave way to a Sunday morning religious conviction. And his moods could turn frighteningly dark, especially in matters related to his tempestuous (and not altogether faithful) relationship with wife, Audrey.

They are themes that Petty, now 31, wasn’t asked to explore when he joined the cast for a two-year run at Nashville’s Ryman auditorium.

“In Nashville, the show was a little more tourist-friendly — a lot more music and a lot less cursing and drinking. Like, ‘Hank drank a little, but not that much. He took a swig about, oh, four times before he died. Don’t you do it! You’ll be sad. Here’s another song,”‘ Petty says, laughing.

Fashioning a more layered show for a New York audience, however, would push Petty’s sparse acting background — consisting of the Opryland gig and some community theater — to its limits.

“When I hooked up with Jason, I asked him, ‘Are you ready to take this to another place?’ It wasn’t very demanding then, and he knew it should be,” says director Randal Myler, who also co-wrote the original script. “He was ready to give Hank a darker spin, and I sensed he could go there.”

‘That lonely place’

Petty’s studious reverence for Williams’ life and music didn’t stop him, however, from taking some liberties.

“Half the expressions in the show are not Hank’s — they’re mine! Like, ‘You two are enough to rub the hide off a brass monkey,”‘ he says, reciting a line from the show that he took from his grandmother, who used it when the kids got on her nerves. “It doesn’t make a bit of sense — no Southern expression ever really did. But you have to put a certain amount of ‘you’ into the role.”

Reflexively, Petty — whose manner is all happy-go-lucky, Southern ease — says he’s never fallen to the “deep dark place” that Williams often went near the end.

“But I think there comes a point in all of us when you can be in the middle of a crowd and still feel alone,” Petty says. “My wife is still in Nashville. I was in New York for the first time when the show started. You know the saying, ‘The world’s a tuxedo and you’re a pair of brown shoes?’ I think that added to my ability to do that here, and go to that lonely place.”