Carrie Underwood will have earned a well-deserved vacation in December.

The singer, who just wrapped up her sixth turn at co-hosting the CMA Awards with Brad Paisley, is spending most of her time in New York City, preparing for her role as Maria Von Trapp for the live televised performance of 'The Sound of Music.' In addition to rehearsing with an all-star cast, Underwood is working with both dialect and acting coaches, and was given extra time to prepare before she joined her co-stars.

“I knew I had the furthest to go," Underwood admits to the New York Post.

Not that her bosses have any fear about her performance. Craig Zadan, who is producing the live broadcast along with Neil Meron, has high praise for the show's star.

“She’s one of those people who showed up the first day and knew every line of the script and every note of every song,” he says proudly. “She’s an unbelievably hard worker.”

The multi-platinum selling singer says the music is a perfect fit for her, especially the song she sings with the young actors who play the Von Trapp children, 'The Lonely Goatherd.'

“I’ve been yodeling my whole life, growing up listening to Kitty Wells and the Carter Family," she explains.

But while she is enjoying singing, her favorite part of the musical has nothing to do with her own songs. Underwood says she is most impressed by the Broadway actresses who have taken on the role of the nuns.

“When they sang, I thought, ‘This is what heaven’s going to sound like," she admits.

The producers, who have also teamed up for other live televised musicals, including 'Cinderella' with Whitney Houston and Brandy, and 'Annie' with Kathy Bates, knew that Underwood would be a perfect fit for the role, thanks in part to her worldwide appeal and her own personal beliefs.

“I think it’s very important, especially in a piece like this, a musical that deals with religion and nuns, that she has that fan base,” Zadan notes. “There’s an element in faith-based belief in the show. The spirituality in the show lends itself to Carrie’s core audience.”

Underwood adds that the show's religious theme, with her character considering becoming a nun instead of raising the Von Trapp children, was especially appealing to her. “Her faith was very important to her and it’s important to me,” she explains.

'The Sound of Music' will air live on Dec. 5 at 8PM ET on NBC.