Oscar-winning writer Jennifer Lee made her Broadway debut when Disney’s Frozen burst onto Broadway this spring season, adapting her Academy Award-winning Best Animated Feature Film into a stage musical and earning a Tony nomination for Best Book of a Musical in the process.

Though the Frozen film was built alongside Oscar winners and 2018 Tony nominees Kristen Anderson-Lopez and Robert Lopez (“We really set out to do a musical, not do a film with music,” says Lee), transforming the story about the true love between two sisters presented new opportunities. “Every song has to move the story forward or show new things about character or take you to a new place you didn’t expect so we were already doing that, but when we came here [to Broadway] we had freedom to go bigger and take bigger chances,” Lee explains.

Taking cues from new songs as well as from the actors originating these roles, Lee wrote a fresh book. “Patti’s been with us from the very beginning and the Anna onstage is different from the Anna in the film and a lot to do with the inspiration she brought me,” says the writer. “I would just sit in the theatre as much as possible even during the rehearsal and write and feel things.”

To give us more insight into her theatrical writing process, Lee agreed to open up her writer’s notebook.

Here, she reveals the motivations behind changes from film to stage, character expansions, and more in this deconstruction of her script. Trekking through the snow, Anna set out to find her sister Elsa in the midst of the eternal winter, caused by Elsa’s anger at Anna’s whirlwind engagement to a complete stranger, Prince Hans. In the blizzarded forest of Arendelle, Anna meets Kristoff and they sing the new song “What Do You Know About Love?”

Ruthie Fierberg is the Senior Features Editor of Playbill covering all things theatre and co-hosting the Opening Night Red Carpet livestreams on Playbill's Facebook. Follow her on Twitter @RuthiesATrain, on Instagram @ruthiefierceberg, or via her website.