Three types of musicians hinge on authenticity: punk bands, folk singers and rappers. Actors, like Oscar Isaac, are by definition phonies. But the star of Joel and Ethan Coen's new film, Inside Llewyn Davis, understands that pressure to keep it real. In high school, he was a straight-edge punk frontman in bands like The Worms and The Blinking Underdogs. And to play Llewyn Davis, the cheerful, Guatemala-born, Miami-raised performer sank into the self-sanctified life of a homeless singer-songwriter in 1961 New York, who'd rather starve to death — or, really, rather mooch off his friends — than sell out. (As for rapping, maybe he'll make that movie later.)

“You're always looking for who means it more,” Isaac says. “That's why you have artists who end up killing themselves, so you knew they meant it — so it wasn't some affectation.”

He couldn't fake it, either. For chunks of the film, the Coens plant their camera to watch Isaac strum and sing old songs about fishing and lynching, which neither he nor his character wrote but both have to channel through their soul.

Folk singers like Llewyn “were the DJs of the time,” Isaac notes. “They would find all these old songs and they would present them to you.” Guided by 11-time Grammy-winning producer T Bone Burnett (who won four of those statuettes for the Coens' O Brother, Where Art Thou?), Davis buried his punk roots to master six folk standards, which he had to perform in their entirety.

“I haven't worked with an actor who could play and sing this style of music this well,” Burnett says. “You can't do it with bluster; you have to do it with the rawest honesty you can.”

Isaac even learned a tricky bit of finger-picking; Burnett describes it as “a little bit like patting your head and rubbing someone else's stomach — in another country.”

Llewyn Davis is talented. But he's also a drag, a narcissist who doesn't have enough charm to win fans or to convince couple Jim and Jean (Justin Timberlake and Carey Mulligan) to give him one more night on their couch. (It doesn't help that he may have secretly knocked up Jean.) Llewyn can't even stop himself from risking an audition with a record producer by singing a bummer about death during childbirth.

Instead of the regular rags-to-riches-to-repentance arc, Inside Llewyn Davis is a subversive faux-biopic. “It just keeps descending and descending,” chuckles Isaac, who calls it a “screwball tragedy.” Loosely inspired by musician Dave Van Ronk — an almost-was who left his fingerprints on the culture without having one-fifth the fame of his friend Bob Dylan — the Coens dangle Llewyn's big break before us until we realize it might never come. What will happen to him if it doesn't?

“He wants to do his thing without compromising, and that's what you need luck for,” Isaac says. “The Coens, in particular, recognize that. They've been really lucky from the get-go. From Blood Simple on, they haven't had to compromise ever, and that's completely unusual.”

For the 33-year-old Isaac, it's been more of a climb. He enrolled in Juilliard on a goof, then spent the next decade doing earnest work in movies few people saw: a Russian security guard in Madonna's W.E., a popular teacher who romances Maggie Gyllenhaal in Won't Back Down, a pop star in the Chris Pratt/Channing Tatum comedy 10 Years. His most recognizable role was in Drive, where he also pisses off Carey Mulligan, that time as her ex-con husband.

“We have this doomed-relationship thing,” Isaac laughs. “We have to find the third one — we're talking about Macbeth.”

In Llewyn Davis, Mulligan hisses that the broke singer needs to sheathe his penis in two condoms and duct tape. Ouch. But as co-stars go, Isaac was more afraid of the orange cats he had to tow around the set after his character accidentally lets a friend's pet escape. Since 2008, his right hand has been scarred from an infected cat bite, which got into his lymphatic system and sent him to the hospital for two days.

“Cut to five years later and the Coens are, like, 'We've got five cats, and these nervous wranglers are holding these cats, and the cats are all freaked out, and we're going to attach these cats to you,' ” Isaac groans. “I wasn't thrilled about that.”

Still, the risk was worth it. The last actor anointed by the Coens, Broadway's Michael Stulhbarg (A Serious Man), went on to take a flashy role in Men in Black 3. Hey, maybe selling out doesn't exist when even Dylan is doing Victoria's Secret ads.

What would Llewyn make of his rival cavorting with Adriana Lima? Isaac knows — he's met a real Llewyn, kinda. On another film set, he noticed an extra cast as a barfly. In between takes, the prickly old man would pick up a guitar and play the kind of folk songs Isaac was trying to learn. Isaac introduced himself and discovered the man, Erik Frandsen, was a friend of Van Ronk's; he still plays open mics and lives in a rent-controlled apartment above the Gaslight Cafe, which the Coens re-created for the film.

“I go to his place, and it's like a time capsule: There's all these old guitars and all these records stacked everywhere,” Isaac beams. “He'll go to these clubs and play, and if he see some kid who shows some promise, he'll invite him over and teach him what he knows. And I think that's what Llewyn would do, too.”

LA Weekly