"We see what is kind of the story of Belle's life before she goes to the castle and she meets Beast," Watson says in a behind-the-scenes clip.
Watson's version of Belle has a number of revamps on the original character. For example, in the 1991 Disney movie, Belle is an assistant to her inventor father, but in the 2017 version, she's developing a "modern washing machine that allows her to sit and read." She also wears riding boots to ride horses instead of ballet slippers.
And while the classic title tune for the original was sung by Angela Lansbury, with Celine Dion and Peabo Bryson performing a version for the film's credits, this time the honor goes to John Legend and Ariana Grande.
"Everyone envisions us in the studio together, but almost every time someone does a duet these days, we do it separately," Legend explained to ET. "We respect the song a lot and we respect the original recording a lot."
Still, Dion is back on the new soundtrack, singing an original song, "How Does a Moment Last Forever." She told ET that the memory her late husband, Rene Angelil, helped convince her to take on the project.
"I kind of talked to Rene and he said, 'You should,'" Dion said. "It was an amazing privilege again. Beauty and the Beast brought me to where I am today. It was a big part of it."
This is the first movie musical for Luke Evans, who plays the comical Gaston, but he has sung on stage in a production of Rent.
"Ever since I told people I'm playing Gaston, they -- without any prompting -- will come out with lines from the song 'Gaston,'" Evans said. "Like, 'I use antlers in all of my decorating.' I did not even remember that line!"