The 'Inside' story of 'Llewyn Davis' star Oscar Isaac

Oscar Isaac is the first to admit that before he was cast in "Inside Llewyn Davis" as the title character, a not terribly successful folk singer, about all he knew of the genre and the early 1960s Greenwich Village folkie scene was "that Woody Guthrie and Pete Seeger existed, and I knew all the Bob Dylan songs. But that gap in between, I knew nothing."

That didn't seem to faze Joel and Ethan Coen, who wrote and directed the film, which opens Friday. They didn't hesitate to hire Isaac, who had already proven his vocal and guitar chops by singing a song titled "The Best I Never Had" in the 2011 feature "10 Years."

"[The Coens] needed someone who was an actor, and could convey the emotional crisis the character is going through," says the 33-year-old Isaac, who was born in Guatemala and raised in Miami. "And it was crucial the music be done live; they wanted to do it documentary style -- if the main actor is lip syncing, the whole thing falls apart."

Isaac, who has also appeared in "Drive," "Robin Hood" and several other features, says working with the brothers was a truly interesting experience.

"There's two of them, two genius filmmakers, they each have a point of view, yet they are completely in synch," he says. "They don't check in with each other that much. There's no ownership with anybody; I was amazed by the generosity of it."

Isaac's character seems to have a perpetual cloud over his head. He has no permanent address, and sleeps on friends' couches. He has sex with his best friend's wife. And his career is going nowhere, especially after his partner in a folkie duo has committed suicide.

"He's a man that's in grief," Isaac says of Llewyn Davis. "His partner just jumped off a bridge, and everything is shifting under him. He's dealing with the phoniness of life and himself, he's just trying to survive. He's someone who longs to be a preservationist [musically], and the scene around him is changing."

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And that Oscar buzz his performance is generating? Isaac is playing it cool. A lot cooler than his volatile character would.

"It's great to get acknowledged for your work," he says, "but to extrapolate possible futures from that is a foolish thing to do. Hopefully, it will lead to some good parts in the future. "