In Birdman (or The Unexpected Virtue of Ignorance), the Alejandro G. Iñárritu tour de force about to rock the film universe, Michael Keaton's character has a running dialogue with a rumbling, soul-crushing voice inside his head.

In real life, the one hearing "demonic voices" whispering in his ear is Edward Norton.

The actor plays an actor in Birdman, an egoistic thespian who joins Keaton's troupe in the dark, whirling, furiously funny backstage drama. Making such a movie, as well as Wes Anderson's The Grand Budapest Hotel - on which Norton worked just before Birdman - "reaffirmed why I like to wait and find things that hold deep interest and excitement," he says. "When you work with the sense of vitality and challenge and fun that Alejandro and Wes both imbue, it strengthens the resolve to ignore those demonic voices in your brain that are calling on your lower impulses."

That is, hold out for the screenplay that makes you quake with awe, or the filmmaker who's zigging when everyone is zagging, rather than taking other, often more lucrative work coming through the door.

"Don't let the voices in your brain that say, 'Oh, I should make a bigger sort of movie,' win the day," he says with a chuckle.

In Birdman, Norton is Mike Shiner, a Serious Actor who wears a hat and scarf indoors and a look of smug satisfaction everywhere - a look that, admittedly, he has earned. He's like one of those legendary theater monsters of yore, a nightmare to all except the audiences who behold his performance each night. There, he is great. Everywhere else - in bars, in bedrooms - he is insufferable.

In Iñárritu's crazily surreal, yet crazily real film, opening Friday at the Ritz Five, Shiner comes in to rescue Keaton's Riggan Thomson - a Hollywood star looking to reinvent himself by mounting a stage adaptation of a Raymond Carver short story on Broadway. Everything that can go wrong in rehearsals does. Then, in walks Norton's Shiner to save the day. Zach Galifianakis, Emma Stone, and Naomi Watts also star.

Playing an actor must have been a meta experience for Norton, right? Were there moments of self-reflection, as Shiner makes his lofty pronouncements about emotional truth, about the meaning behind the words?

"This may sound too convenient, but the truth of the matter is, I've rarely looked inward at my own experience when I'm trying to source the inspiration for a character," Norton says. "That would seem obvious if you're talking about something like American History X," Norton's film about a neo-Nazi skinhead. "But equally, even right down to something that moves around in a world that I have moved around in, I don't look for what I would call the aspects of character in myself. . . . I'm much more naturally inclined, in my own compulsions, to mimic and to absorb - to take reference points in other people, and turn them out into a character.

"I come from the Stella Adler school, which is, like, your greatest gift is your imagination. . . . For me, even the character of an actor is much more interesting to explore through reference points in other people - actors who I grew up watching who I heard were kind of holy terrors and alcoholics and stuff, and cherry-picking some of those funny stories. Telling them to Alejandro, having him even work some into the script."

Norton says he modeled some of the Shiner character on Iñárritu, as well. "I got a lot of inspiration just in Alejandro himself, because I think a lot of what Shiner says in the movie is very much Alejandro's voice. He is declamatory and passionate and argumentative - and usually right, which is basically what Shiner is."

Since its world premiere at the Venice Film Festival in late August, Birdman has been a bonfire raging out of control - the buzz, the raves, the what-was-that-I-just-saw incredulity.

"When you're involved in something that's a little bit out there, and has a lot of ways that could not work, it's nice to see it catch people the right way," Norton says of the film, and the way audiences and critics are beginning to embrace it.

"It's nice to see that people will go with something that doesn't hew to a narrative form that they're familiar with . . . that people can recalibrate to the unusual frequency this film is on."

Norton likens the project to another of his films: Fight Club, the David Fincher enterprise that also toyed with reality, perceived realities.

"Fight Club was a terrific book and a really well-done adaptation, but during rehearsal, in a similar way to what happened with Alejandro and Birdman, it became more and more clear that Fincher was going to use that text as this springboard. . . . Here was this disruptive filmmaker, and you started to get this sensation that he was going to take a really, really big swing. And anytime you're taking a big swing, a question mark hovers over it.

"But it starts to produce a feeling of excitement that at least we're engaged in something that we don't recognize, and we hope other people won't recognize, and therefore could be pretty exciting."

With Birdman, "pretty exciting" doesn't begin to describe it.

215-854-5629 @Steven_Rea