The producing duo, whose last endeavor for NBC was the musical series "Smash," previously brought Gypsy, Annie and Cinderella to television audiences, which later led to big-screen projects such as Chicago and Hairspray. "This project really dates back to those movie musicals we first did for television," Zadan said. "Neil and I were saying that maybe we should go back and do more movie musicals for TV and then we thought, 'Well, we've already done that. What could be different or what could be new?'"

They found the answer by reflecting on their childhood. Meron and Zadan looked to the live national broadcasts of Peter Pan starring Mary Martin, as well as Rodgers and Hammerstein's Cinderella with Julie Andrews, both of which were seminal moments in 1950s television entertainment.

"We wondered, 'Would it be possible to mount a live musical broadcast today?'" Meron and Zadan – and they hope millions of American viewers – are about to find out.

In an era of DVR and television on-demand, NBC Entertainment chairman Robert Greenblatt, according to Meron and Zadan, was seeking a unique television event that had the potential to be a ratings boon. Live events are still a reliable bet for large ratings numbers. "He approached us and said, 'If you ever come up with an idea for something that could be a big event, call me.' We said, 'We don't actually have to call you. The truth is we've been talking about The Sound of Music done live for a while, and figuring out if it was the right time and the right place and the right circumstances,'" Zadan said. Greenblatt committed to the project on the spot.

The 1965 film of "The Sound of Music," which starred Julie Andrews and Christopher Plummer, has become a staple of the American holiday season thanks in part to an unprecedented 20-year deal with NBC to broadcast the musical annually. While the broadcast calendar slot has shifted over the years, "The Sound of Music" and the adopted Christmas song "Favorite Things" have become part of holiday nostalgia.

	Craig Zadan
	Photo by Monica Simoes

While fans can quote the film and even perform the choreography to "So Long, Farewell," the property's original, 1959 Tony Award-winning stage version is lesser known. Penned as a vehicle for Mary Martin, the stage production of The Sound of Music, which includes several songs that were left out during the restructuring of the film, casts more political shadows.

"The moment you tune in and watch this, you're going to know in the first couple of minutes that, 'Wow this is not the movie,' and we're excited about that," said Zadan. "Everyone in the world has seen the movie a thousand times, but very few people that I know have ever seen The Sound of Music on stage. We didn't want anyone to think that we were being disrespectful of the movie, or Julie Andrews."

Casting the role of Maria posed several challenges. The producers not only needed an actress capable of following in the footsteps of Mary Martin and Julie Andrews, both of whom were beloved by the public, but they needed a performer with wide viewer demographic appeal, who was the right type to play the part and could sing a legit Broadway score.

"Maria is basically goodness personified, and when you look at the landscape of people out there that bring that with them, it's Carrie Underwood," Meron said of the Grammy Award-winning country singer, who launched her career when she won the fourth season of "American Idol." Underwood was their first choice for Maria. "It kind of fits into what her fan base knows and loves about her in terms of her ability to sing great. Also, she's stage-based and she has all the qualities of Maria."

The Sound of Music Live! marks a new endeavor for the singer, who will make her primetime acting debut as Maria. "I'm always looking out for new opportunities," said Underwood, who grew up watching the film, but didn't have musical theatre as a large part of her life. "I love being able to step out of my comfort zone and be a part of projects that are different and exciting. I wouldn't say that I was necessarily looking for something like this, but I sure am glad that it found me." The star is also aware of the expectations and the legacy associated with the musical. "I truly consider myself to be blessed in that I get to help expand the legacy that is The Sound of Music," she said. "From the lives of Maria and the Captain and the children to the musical to the movie and to this wonderful TV event that we're doing... we're all helping to tell this beautiful story and pass on these incredible songs. It really is an honor to be a part of."

"She has been working like a demon," said Ted Chapin, the president and executive director of Rodgers and Hammerstein, which oversees the catalogue of the late Tony Award-winning songwriting team. "It’s fair to say that Carrie Underwood has the kind of name to get a project like this done."

	Ted Chapin
	Photo by Joseph Marzullo/WENN

For her debut, Meron and Zadan have surrounded Underwood with a principal cast of theatre royalty and an ensemble company full of Broadway veterans. As Meron pointed out, "We wanted the best of the best who live, breathe and eat the theatre idiom because we are doing Broadway live on television," noted Meron. "[Carrie] is clearly aware that she is in really, really good company," Chapin remarked.

"I feel so lucky that I am surrounded by so much talent," Underwood said. I feel like I get to be a sponge and soak up so much from them. I get to sit back and learn from the best of the best."

The list of the best of the best includes Tony Award winners Laura Benanti and Christian Borle, as Elsa Schrader and Max Dettweiler, respectively, as well as five-time Tony Award winner Audra McDonald as Mother Abbess.

"We went after Audra with a vengeance," Zadan laughed. "If we're going to do The Sound of Music for today, we're going to have to reexamine what these roles are," Meron added, noting that McDonald also charts new territory as the first black actress to play the role of Mother Abbess in a major U.S. production of The Sound of Music.

"It's never a show I thought I would be in, never in my life," McDonald said. "It's a show that I've associated with, in terms of being a fan of it, being moved by it and it being a part of my life growing up, like every other kid in America." It also marks a full-circle moment for the soprano, who earned her first Tony Award in the 1994 Broadway revival of Carousel. "All of a sudden, here I am finding myself in the actual musical. It feels strangely like a homecoming, although, Lord knows, on paper it doesn't look like it should be, but it feels that way." The telecast is also an unexpected homecoming for Benanti, who took over the role of Maria in the 1998 Broadway revival of The Sound of Music. At 18-years-old, the production marked her Broadway debut. "I never really thought I'd be looking at this piece through the eyes of Elsa, and in doing so I'm seeing different things. So it’s been exciting for me."

For Borle, it's a fresh start. "There are certain cultural black holes that I have, and actually The Sound of Music is one of them," he laughed. "I saw the movie for the first time maybe two years ago. What was interesting actually about seeing it for the first time was really kind of understanding the whole story as opposed to being a kid who kind of liked the jaunty tunes."

	Stephen Moyer
	Photo by Paul Drinkwater/NBC

Both Max and Elsa, who are relegated to non-singing minor roles in the film, have stronger stakes in the stage musical. Their duet, "No Way to Stop It," which was cut from the film, brings a broader sense of political and social context to the changing world and the shadows of the Nazi regime that is casting shadows across Austria. "Be wise, compromise," they urge Captain von Trapp.

U.K.-born actor Stephen Moyer makes a return to musical theatre as the regimented Captain von Trapp. Fans of his work as vampire Bill on "True Blood" may be surprised to find out that The Sound of Music is familiar territory for the actor who started out on the musical stage.

"I started in musical theatre. I did amateur dramatics in England; you call it community theatre in America. But then I got to a point where I had done so many musicals that I wanted to do straight drama, which is why I ended up going to drama school. Of course, the irony being that after doing three years of Shakespeare and Meisner classes, the first show I did when I came out of school was Oliver!"

He adds, "It's kind of terrifying when you come back to it. I've been off the stage for 18 years." Having recently played Billy Flynn in the Hollywood Bowl staging of Chicago, Moyer laughed, "It's a baptism by fire returning in this manner. There were 18,000 people a night at the Hollywood Bowl and then potentially in front of 20-million people on NBC."

With that kind of ratings potential and a reported production cost of nearly $9 million, NBC and the creative team, which includes Tony Award-nominated director-choreographer Rob Marshall and Emmy-nominated "Saturday Night Live" and "30 Rock" director-producer Beth McCarthy-Miller, aren't leaving anything to chance for the live broadcast. "We've had a proper rehearsal process," Moyer said. "We've been able to explore and play. We have the opportunity to form and build the character in the rehearsal process without having to come in with preformed conceptions of how it's going to be."

"Rob Ashford is a great director and his focus is on finding the truth of it," Borle adds. "When you don't have to play for laughs, you have to know that they might be there, so you have to be very careful with your timing. Even with the buttons of numbers. We'll finish a number and just plow right on if there's not a commercial break. You're not holding for applause."

	Rob Ashford and Laura Benanti in rehearsal.
	Photo by Paul Drinkwater/NBC

Benanti echoed that statement. "It's one thing to open on Broadway. You've had your previews and you have your audience, but you know, we don't have an audience! We're just going to be performing this live, and our audience is millions of people sitting in their living room. I mean, I'm certainly nervous, but I’m trying not to focus on it too much."

The ambitious technical undertaking also presents new challenges for actors who are used to quick costume changes in the wings, just out of audience sightlines. According to Moyer, "In some sense it's TV with filmmaking, but because of the live aspect of it, we're doing a theatrical performance without a live audience. It's like nothing any of us had ever done, really."

McDonald added, "Normally, at this point, you're moving into a theatre, and this is when you would go into tech. For this, we're moving into a sound stage that's the size of a football field. If you want to get dressed, you have to leave the building to go get dressed. If you want to go to make-up, you have to run a touchdown to go do make-up - the enormity of it all."

The hybrid of theatre and live television, which has its challenges, also provides unique moments for viewers that will take them beyond the excitement of a purely live event.

According to Chapin, "There are a couple of transitions that they have devised that, to me, are absolutely brilliant notions of saying to the audience, 'We're not taking pictures of a theatre and we're not making a movie. We're doing something that is its own creation, and in our world things can happen.' That's quite magical." Zadan and Meron are hoping that the magic will continue long after the von Trapps say "So Long, Farewell." While they declined to share which titles are up their sleeves, both are hoping that the airing of a live musical on NBC will become an annual event.

"It's one big experiment," Zadan said. "We're very aware of the fact that if it succeeds, it will prompt the network to ask us about doing it again. It could be the beginning of something new in terms of bringing theatre to America on TV. Once we see the ratings, our wish list will come out of our pockets.