How’s this for pressure? You’ve scored the lead role in the new Coen brothers movie—your first lead role in any movie—but they want you, against all convention, to sing and play guitar live to camera. If there are any variations in tempo between takes, everything’s fucked.

Solution? Bring in legendary superproducer T Bone Burnett to sit there off-camera with a stopwatch, timing you!

“Look, they’re not gonna fire me at this point, right?” Oscar Isaac, reasons, chuckling, in a call to the Georgia Straight from Los Angeles. “So the only thing they could possibly do is help me do it better. This was like having the absolute best trainer in your corner watching the fight and finding a way to get you to win. That actually allowed me to really let go of any worries. They’re not going to let me look like an asshole, because, you know, this is one of the crucial things about this movie.”

As the titular antihero of Inside Llewyn Davis, opening Christmas Day, Isaac’s musical chops are, indeed, crucial. Set in the wintry Greenwich Village folk scene of the early ’60s, and following Davis through a week or so of bone-freezing hard times, it’s a film that puts a lot of stock in authenticity. Miraculously, Burnett discovered that the young actor—first seen in the movie delivering a poignant version of the traditional ballad “Hang Me, Oh Hang Me” at the fabled Gaslight Café—had perfect tempo. Which is a rare thing even for people who don’t treat music as a secondary pursuit.

“Well, ironically, if you ask any of the drummers I’ve been in bands with, they’d be, like, ‘Yeah, right,’ ” Isaac counters, amused. “Because I’ve never been particularly good at that.”

Not until he prepared for the role by learning an era-appropriate guitar finger style called Travis picking, at any rate. “And that’s like playing drums,” Isaac explains. “You have to have complete independence of your fingers so the thumb is the metronome that’s doing the bass line, and the index and middle finger are doing melody and countermelody. So it’s syncopated. It’s like you have to trick your mind into not hitting the high hat at the same time that you hit the kick, you know?”

Isaac adds that he drilled himself “over and over and over and over and over and over and over again” on the performance side of the role. Far less arduous was digging into the pre-Dylan sounds of the period, with some guidance from Dave Van Ronk’s memoir, The Mayor of MacDougal Street—also a starting point for the Coens.

“I listened to everything recorded by Dave Van Ronk,” he says. “I actually got guitar lessons from a guy that played with Dave Van Ronk and opened up for him in a bunch of little Village cafés and spots around town and listened to stuff that Van Ronk listened to: Reverend Gary Davis, Lightnin’ Hopkins, and I found Karen Dalton, who I’d never heard of before. Oh, man, so good, and such a tragic story as well. But you realize there’s this whole repertoire of music and musicians that are basically unknown to the public. They weren’t monetarily or commercially successful by any means, but the music remains.”

The actor adds that Davis’s own shaggy-dog odyssey—with the unrewarded talent, couch-hopping indigence, leaking shoes, and never-ending trouble—belongs to an all-too-familiar archetype. “There’s story after story,” he says. “I mean, you watch Amadeus again, you realize: ‘Oh, shit, Mozart actually wasn’t that loved while he was alive.’ ”

On the plus side, with Inside Llewyn Davis the Coens are paying an indelible kind of tribute to all those great artists we’ve probably never heard of. And while speaking of Raising Arizona, his own favourite in the team’s long filmography, Isaac could very easily be describing their latest. “It just made me feel so sad and weird, and it was so funny and had such an interesting tone,” he says. “It’s the kind of movie that makes you dream.”