CANNES, France -- In close to three decades of filmmaking, brothers Joel and Ethan Coen have shared a lot of looks. But with "Inside Llewyn Davis," which had its premiere in Festival de Cannes competition Sunday, one particular glance said it all.
"At one point, we looked at each other," Joel recalled, sipping coffee in a joint early morning interview, "and said, 'Have we written something which is essentially unmakable because it's uncastable?' "
The Coens' concern was legitimate. Set in the small and self-contained folk singing universe of New York's Greenwich Village in 1961, just before Bob Dylan's arrival turned everything upside down, "Inside Llewyn Davis" demanded something very particular of the actor playing the title role.
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"He had to be believable as a musician, because this is not the kind of movie where you hear a few bars of a song; they play out in their entirety," Joel continues. "But the character is in every scene, so he has to be a very accomplished actor. It's not easy to find that in the same person, so we were very frustrated until Oscar walked in."
"Now it weirdly seems as if it was written for him," adds Ethan. "But we would have been screwed if he hadn't come in the door."
The intense and charismatic Oscar Isaac, known to movie audiences for roles in "Robin Hood," "Drive" and "The Bourne Legacy," is the heart and soul of this exquisitely made film, which follows folk singer Davis on a one-week-in-hell journey that is both haunting and ever so bleakly funny.
The Coens mandated entire songs be sung -- the film opens with Davis singing a three-minute version of "Hang Me" in a Village club -- for several related reasons.
For one thing, singing was the best way to demonstrate that, though unsuccessful, Davis was an exceptional singer. "People would read the script," Joel relates, "and say, 'I don't get it. Is he supposed to be good or is he supposed to be crummy?' "
Also, because Davis can be a difficult person (just ask Jean, one of the women in his life, smartly played by Carey Mulligan), hearing him sing so beautifully, Joel says, "reveals something about him we don't see somewhere else."
In addition, "Frances [Joel's wife, actress Frances McDormand] pointed out that hearing the entire song makes this like a traditional musical. When the song is finished, we've notched up to a different place in the story."
But, perhaps most crucially, the movie pays the music the tribute of taking it completely seriously, Ethan says, because "the film is about that character. That music is important to him. That's his life."
Though they are a bit too young to have experienced it personally, the Coens feel the same way about the music and the scene.
"There was never any desire to or interest in burlesquing that scene. We wanted to do something in a straightforward way," says Joel, with Ethan adding, "We grew up with Bob Dylan; all those records were big deals. So what that came out of is a big deal to us as well."
The initial idea for the movie, which in fact became its first scene, was the notion of starting a film with a folk musician getting beaten up outside Gerde's Folk City, a Village club. "We didn't quite know where that might go," says Joel, not surprisingly, "so it sat there for awhile" ("Like years," adds Ethan) until the story came together.
Though the film's Village folkie scene and the songs the title character sings were inspired by the late Dave Van Ronk and his memoir, "The Mayor of MacDougal Street" (which producer Scott Rudin optioned for the Coens), anyone who remembers the bear-like Van Ronk and his gravely voice will know that Davis is another character entirely.
Still, Ethan Coen admits, the vast difference in vocal styles was "a weird impediment to casting Oscar. Dave's voice was in our heads; he was the ultimate blues shouter, and Oscar has this beautiful tenor voice." Finally, says Joel, they said, "It's not Dave; let's get our heads behind this kind of musician."
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With a superb soundtrack executive-produced by T Bone Burnett, music is one of the connections that "Inside Llewyn Davis" has to the earlier Coen brothers film "O Brother, Where Art Thou." Another is the Odyssey-like journey (there's even a cat named Ulysses involved) that Davis takes.
"We knew when we started that the script would circle back around to the starting point, the whole thing is a circle," says Joel. "And we've retrospectively noticed, though it was not foremost in our minds, that the structure of a song often does that."
"He keeps ending up in the same place," Ethan adds about the title character. "It's a nightmare journey, running hard and not getting anywhere."
Which raises the question, why do so many of the Coen brothers' movies involve terrible things happening to their characters? Being one of their protagonists, Joel admits, "is not for the weak of heart," but Ethan says that's the way it has to be.
"I don't know how else you'd do a story," he says, smiling. "Something good happens to a character? Why would you want to do that?"