NEW YORK — Few people would mistake the Long Island commuter town of Bethpage (elevation: 105 feet) for the Austrian Alps. But on a vast soundstage in an anonymous industrial park about 45 minutes from Manhattan sits a gently sloping, man-made hill that will double for one of that country's scenic peaks on Thursday.

That's when NBC unveils "The Sound of Music Live!," a three-hour televised version of the 1959 Rodgers & Hammerstein musical featuring country music megastar Carrie Underwood in the iconic role of free-spirited nun-turned-governess Maria.

On a recent afternoon the "American Idol" winner, looking mildly rebellious in black skinny jeans and a Rolling Stones T-shirt, wandered through the ersatz landscape, rehearsing the titular opening number as Beth McCarthy-Miller, one of two directors on the show, watched the action on a flat-screen monitor about 50 feet away. They were in the middle of a long day of camera-blocking, the painstaking process by which cast and crew work out the precise choreography of the upcoming live telecast. 

PHOTOS: Scenes from 'The Sound of Music Live!'

As Underwood bobbed behind an artificial tree, musing via song about her day in the hills, the camera pulled back, accidentally catching another camera in the frame. "Oops. We can't have that," said McCarthy-Miller, directing the singer to begin again at the top.

Needless to say, there will be no such do-overs Thursday, even if something truly catastrophic happens — like, say, a blackout suddenly strikes the East Coast or one of the Von Trapp kids breaks a limb during "The Lonely Goatherd." (The show will air on tape delay in the Pacific and Mountain time zones.)

"We told everybody, 'Just keep going, no matter what happens. You can't start over,'" says Craig Zadan, who is producing the show with his creative partner, Neil Meron.

In an era when time-delayed viewing is increasingly the norm, "The Sound of Music Live!" is the latest — and easily the riskiest — effort by network television to create DVR-proof programming. Of the legacy networks, NBC has displayed a greater willingness to experiment with live, scripted television, most obviously with "Saturday Night Live," but also with real-time broadcasts of "E.R.," "Will & Grace," "The West Wing" and "30 Rock" (twice). 

"I think networks are searching more and more for the things that will attract people to watching TV as it happens," Meron says. "We've been looking at the direction of where appointment television was going and from our point of view it seemed the thing that was attracting the most eyeballs was live TV."

PHOTOS: Movie scenes from 'The Sound of Music' (1965)

Ratings aren't the only motivation; there's also something ineffable about the live viewing experience, says Stephen Moyer, who stars opposite Underwood. "I want to watch as it's happening — that's magic. We live in a world where we have the ability to watch live, and yet we don't do that very often."

The inherently unpredictable nature of "The Sound Of Music Live!" is just one of the many reasons it's generated a flurry of attention since it was first announced by NBC last year. Purists have also scoffed at the (mistaken) idea that NBC is remaking the widely beloved 1965 film version of "The Sound of Music" with — gasp! — a singer who rose to fame via reality TV playing the role made famous by Julie Andrews.

But as Underwood and virtually every other person involved with the project is keen to emphasize, "The Sound of Music Live!" is actually a staging of the musical upon which the Oscar-winning movie was based. (That's why Audra McDonald's Mother Abbess, not Maria, will sing "My Favorite Things.") 

Underwood recalls asking Zadan and Meron for help clarifying their mission to a skeptical public. "In the beginning I was like, 'You gotta help me out here! Everyone thinks we're doing the movie and I'm getting hate tweets.' And I would have felt the same way, even if I wouldn't have sent hate mail about it. So that's been a challenge, helping people understand."

The cries of blasphemy are even more curious given that revivals and repertory works are an integral part of the theater world. As Moyer puts it, "Nobody mentions the fact that there's been five Macbeths this year."

While not quite unprecedented, the three-hour event represents the revival of a long-extinct format not seen on network television in five decades.

ON LOCATION: Where the cameras roll

"It's really a throwback in a way," says television historian Tim Brooks, explaining that live theatrical productions of shows such as "Peter Pan" and "Cinderella" were commonplace in the 1950s, when the broadcast networks were still based in New York City. The format died out in the '60s as the public's musical taste changed and the industry began to focus on the 18-to-49 demographic.

Zadan and Meron have made something of a career out of reviving the musical in its various forms, starting with 1993's made-for-TV movie "Gypsy" with Bette Midler, followed by the Oscar-winning movie "Chicago" in 2002. Less successful (though no less ambitious) was "Smash," the ill-fated NBC series about behind the scenes drama on Broadway. Zadan and Meron also have experience in the particular challenges of live television, having produced this year's much-discussed (and highly rated) Oscars telecast.

The duo had already been kicking around the idea of staging a live musical when NBC Entertainment Chairman Bob Greenblatt called them up last year to propose making a TV movie of "Oklahoma!" They pitched "The Sound of Music Live!" instead, and Greenblatt, a musical theater devotee, quickly gave it a greenlight.