'Let it Go' composers pen big musical number for Oscars host Neil Patrick Harris

NEW YORK -- The Oscar winning composers behind "Let it Go" from Disney's "Frozen" are working with Oscars host Neil Patrick Harris for a big musical number.

The husband and wife team of Robert Lopez and Kristen Anderson-Lopez couldn't give away too many details about the song, but did reveal that it continues to evolve.

They say that Neil Patrick Harris is very hands-on and should be considered a third writer because he calls and texts at all hours to suggest tweaks and changes to the number. Anderson-Lopez says that Harris is, "so focused and so smart and he really has a vision for what the song needs to be and we're just happy to be helping him."

The duo did take into consideration the jokes made at the Grammys and the Golden Globes. "You have to adapt and react and that's part of the fun," Anderson-Lopez said.

The happily married composers say that instead of donning a ball gown and tuxedo, they'll be happily watching Harris perform their musical number from the comfort of their home with their two daughters.

Anderson-Lopez and Lopez mentioned their young daughters in their acceptance speech at the Oscars last year when they won for "Best Original Song". That win also gave Lopez the coveted EGOT meaning he's won an Emmy, Grammy, Oscar, and Tony.

"Frozen" fans will also delight in learning that a new digital short called "Frozen Fever" which plays right before Walt Disney Pictures' "Cinderella" premieres in theaters on March 13th. The Lopez's wrote a new original song for the short that picks up right where the movie "Frozen" left off.

And that's not all! They are also working on a new original musical called "Up Here," which will be featured in the La Jolla Playhouse's 2015-16 season in California. "It's a romantic comedy about relationships and consciousness," Lopez said. They have hopes that it will make it to Broadway in New York City.

Don't miss The Oscars this Sunday at 7 p.m. Eastern/4 p.m. Pacific on ABC!