NEW YORK – For the guys in the Fab Faux, the songs of the Beatles are as much classical music as classic rock.

“The way an orchestra would do Mozart or Beethoven?” explains guitarist Jimmy Vivino. “That’s how we do the Beatles.”

And that’s how the brilliant Beatles cover band – it’s a five-piece, featuring late-night musical stars Vivino (Conan O’Brien) and Will Lee (David Letterman) – approaches its gig this Saturday night: a complete recreation of “Sgt. Pepper’s Lonely Hearts Club Band” before a sold-out crowd at Manhattan’s Beacon Theater.

It’s their largest headlining show ever, nearly a decade after Lee’s obsession with the Beatles led him to seek out similarly crazed New York musicians and 40 years after the Beatles released the album that altered the course of musical history.

“This is the first album that I remember listening to as a single piece,” Vivino said before a weekday rehearsal with his regular cohorts, the Max Weinberg 7.

“It was meant to be listened to that way. There are no singles from `Sgt. Pepper.'”

The band, with bassist Lee and guitarist Vivino, is rounded out by acclaimed New York music scene vets Rich Pagano on drums, Frank Agnello on guitars and Jack Petruzzelli on keyboards and guitar; all five share vocal chores.

To describe them as a tribute band conjures images of four guys in bad wigs and ’60s facial hair, and that’s not what the Fab Faux is about. Lee explains the mission this way:

“In my mind, our job is to bring the records to the stage. That’s kind of what we are. I’m not saying we ever achieve that, but that’s the goal.”

The five are self-professed Beatles geeks, the type who hoard bootlegs and raw studio tracks, guys who can listen to “Revolver” 500 times and hear something different with each spin (vinyl, of course). Pagano once wrote an impassioned “Modern Drummer” piece extolling the virtues of Ringo’s stick work.

How much do these guys love the Beatles? They’re all well-known musicians, with impeccable resumes and plenty of work. And in their spare time, they like to unwind by picking up their instruments … and playing the Beatles.

“We’re fans first,” said Lee, who’s played with all four Beatles during his career. “For me, the Beatles are the top of the musical food chain. Something happened back in ’64, when the Beatles hit America.”

Pagano, who’s worked with Patti Smith, Ray Davies and many others, shares the sentiment.

“I don’t know anybody who’s as into it as we are,” Pagano said. “There really isn’t any better pop music, as far as we’re concerned. You can get so sick of certain types of music. But we don’t get sick of the Beatles.”

Their audience clearly feels the same way. The band has headlined four of the last five years at the annual Beatle Week in Liverpool, recreating the Fab Four for 35,000 Beatlemaniacs. They’ve done shows in Las Vegas, Atlanta, Philadelphia and Toronto.

The band’s sound will be enhanced at the Beacon by the four-piece Hogshead Horns and the Creme Tangerine Strings. The Fab Faux will kick off the show with “Sgt. Pepper’s Lonely Hearts Club Band” and proceed through its 13 tracks, closing with “A Day in the Life.”

The quintet will also play a second set of assorted Beatles tracks. And the show will be preceded by a Q&A; with Geoff Emerick, the sound engineer for the “Sgt. Pepper” sessions.

One strange thing has emerged from the project: although the Beatles provided a musical soundtrack for the lives of most Baby Boomers, and each member of the Fab Faux is intimately aware of the Beatles’ catalog, playing the songs live has left the band hearing the music through new ears.

“I was surprised to find out how little you know of these records until you dig deep in,” said Lee. “We weren’t able to hear it before. Now we’ve reached a certain height in awareness – and there’s always so much more.”

Vivino agreed, comparing the band’s efforts to an archaeological dig.

“It’s basically like going into King Tut’s tomb of music,” Vivino said, his words giving way to a laugh. “You know what I mean? It’s either successful, or how dare you? If you come out with the wrong thing, you could get killed.”