Amanda Seyfried gives hint of her new movie with Lin-Manuel Miranda

Amanda Seyfried has offered a first glimpse into her upcoming musical film with Lin-Manuel Miranda, describing the experience as one of the most fulfilling moments of her career so far.

Speaking to PEOPLE at Tiffany & Co.’s Blue Book gala on April 16, the 40-year-old actor revealed she was initially unaware of the full scope of the project, titled Octetwhen Miranda first approached her.

The film was officially announced by Miranda, 46, on April 2, with rehearsals beginning shortly after on April 14 alongside a star-studded cast including Rachel Zegler, Jonathan Groff, Sheryl Lee Ralph and Phillipa Soo.

“I didn’t even know what it was exactly,” Seyfried said, adding that she only learned details after meeting Miranda specifically for the project. “I was like, ‘I don’t care what it is. I’m in.’”

She explained that once she discovered it was an a cappella musical, her enthusiasm only grew stronger.

“I’m a born singer. It’s what I love to do,” she said, calling the opportunity “absolutely better than I could have ever hoped for.”

Seyfried added that production is already underway and described the creative environment as highly collaborative and joyful.

“Some of the best moments of my life have just happened this week,” she said.

The film is based on the 2019 Off-Broadway musical Octet and marks Miranda’s return to directing following tick, tick… BOOM! in 2021.

Seyfried praised the ensemble cast, noting that everyone involved is deeply passionate about the project and united by their love of music.