Ethan Slater can do it all!

The actor, 32, auditioned for his role as Boq Bad by performing as the character on his audition tape, as well as Glinda (Ariana Grande) and Nessarose (Marissa Bode).

“I did two scenes and sang Boq’s songs, ‘The Ozdust Ballroom’ and ‘March of the Witch Hunters,’ which is the second movie,” Slater says in PEOPLE’s new special Bad edition.

“But,” he continues, “I have to say I didn’t have anyone to read with at the time, so on the tape I sent I play Glinda and Nessa off camera, and then I read with a video of myself.”

Slater calls the decision to play three characters at once in his audition tape “so brutal,” adding, “I can’t believe I got away with it. But I knew I wanted to take my time… and I could. I can’t get anyone to spend that time with me, so I just did it with myself.

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Bad marks Slater’s first major film. He had auditioned for Boq on Broadway long ago, although he didn’t get the part.

However, he was later given the title role Spongebob square pantsa musical version of the popular Nickelodeon television series, which earned him a Tony Award nomination.

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In the upcoming film adaptation of the Tony-winning Broadway musical, Grande, 31, plays Glinda, opposite Cynthia Erivo, who plays Elphaba. (The musical’s original Broadway cast included Kristin Chenoweth and Idina Menzel in the roles, respectively.)

Others appearing in the project, directed by Jon M. Chu, include Jonathan Bailey as Prince Fiyero Tigelaar, Jeff Goldblum as the Wizard, Michelle Yeoh as Madame Morrible, Peter Dinklage as Dr. Dillamond, Bowen Yang as Pfannee and Bronwyn James as ShenShen.

According to Slater, working with such a large ensemble of talented actors was a unique experience.

“What felt really special is how much everyone cared about their characters,” he tells PEOPLE. “When you’re working on something that’s been around the world for 20 years and these are characters that fans love and care about, it’s very important that the actors who portray them in a film of this magnitude are there care as much as anyone else. And everyone did that.”

“To see Cynthia navigate her love for Elphaba, to see how Ariana navigated her love for Glinda and how to infuse their performances, it was revelatory, it was so beautiful,” he continues.

Speaking specifically about Grande, who he is currently dating, Slater says: “One of the things that was really fun to see is that she has a masterful grasp of comedy, and she’s so funny and so physical, and that it never feels like a joke on top of the character. It always feels like it comes straight from Glinda is Glinda. Even in those incredibly funny physical moments.”

Buy PEOPLE Bad special edition here. Bad will be released in two parts, the first of which will be released in theaters on Friday, November 22.