Lin-Manuel Miranda is known for a variety of talents, the most notable are his impressive rapping skills. In Mary Poppins Returns, he’s playing the lamplighter Jack, an adult protégé of Dick Van Dyke’s Burt, and he gets to lean into the beat in the upcoming Disney sequel. Producer Marc Platt told a small group of journalists on set, “Believe it or not, in 1934 music hall style, he even gets to do a little rap. It’s quite extraordinary.”

Miranda’s journey to Disney’s follow-up to their 1964 film began with a meeting with director Rob Marshall and screenwriter John DeLuca. They pitched him on the idea of playing a lamplighter, a role Miranda had already played in his musical In the Heights. Mirands explained a little about the character’s background, “Jack apprenticed under Burt from the original films so he knows all about Mary. He knows that Mary shows up and stuff’s going to happen and cool adventures will be had. So it’s really nice to play the Burt position in this film. You kind of get to go on all the fun adventures with the Banks family.”

It’s no wonder Marshall pursued Miranda for the role of Jack. He gushed about the actor and composer, saying that they needed Miranda’s earnest excitement for the role. In this film, Miranda gets to be charismatic and bring light into the world as he sings and dances. He does all the things you want to see Miranda do. Marshall recalled, “We were looking for a wonderful companion to Mary Poppins who goes on these adventures, someone with that same spirit, that sort of purity of spirit. At the beginning of the film he’s rapping like he’s a one-man band, which just felt so right for him. The big question was what he would be interested in doing as his first project after Hamilton, and I think he was excited to be seen as an actor again and not as a composer or writer.”

Miranda’s character, like Burt, is an everyman juggling a variety of skills. He’s very much a–pardon the pun–jack of all trades. Miranda imagines a younger Jack was like a mini-Burt running around after his mentor. He explained, “Jack grows up and doesn’t lose that spark. I think what Burt and Jack share is that they don’t lose the imagination that comes with childhood. I think that’s one of the themes, too: grown-ups forget. Grown-ups forget imbuing the world with imagination at every turn. And what sets Burt apart and Jack apart is that they don’t. [Jack] remembers Mary Poppins and he remembers everything she’s capable of. She’s not just a nanny in his head. She is a bringer of wonder.”

Miranda added with a smile that the two days Van Dyke filmed on the sequel were the best two days ever. “I aspire to have that much energy in my life, someday, much less at 91. It was a joyous two days.”

Mary Poppins Returns premieres in theaters on December 19.

Images: Disney

Amy Ratcliffe is the Managing Editor for Nerdist and the author of Star Wars: Women of the Galaxy. Follow her on Twitter.