Shawn Mendes Says Lending His Voice to Lyle, Lyle, Crocodile ‘Felt Natural’ — See the Trailer

“I relate to his story,” the Canadian pop star tells PEOPLE of his character Lyle the crocodile

Most of us have experienced a loud neighbor at some point, but only Constance Wu in Lyle, Lyle, Crocodile can complain about a singing reptile living upstairs.

In the PEOPLE exclusive first look at the trailer and photos for the big screen adaptation of the Lyle, Lyle, Crocodile children’s book series, Wu, 40, discovers Lyle (voiced by Shawn Mendes) singing in the bathtub.

“What was really amazing was that Lyle as a character only sings, so I felt really comfortable playing his character,” Mendes, 23, tells PEOPLE. “I was able to do what I do best, plus I relate to his story and his character so much it felt natural. When I was approached to help make the music for the adaptation of such a classic book, it was a no brainer and just such a fun departure from what I am used to.”

Lyle helps young neighbor Josh (Winslow Fegley) find his own voice as he struggles to adapt to a new school. Mendes worked with Tony-winning composers Benj Pasek and Justin Paul — the duo behind musicals Dear Evan Hansen, The Greatest Showman and La La Land — to create the songs for the upcoming family film. While Mendes has released four No. 1 albums since 2015, writing music for a movie proved to be a “really incredible challenge” for the pop star.

“Making music for a film like this with them was such an inspiring process,” the “There’s Nothing Holdin’ Me Back” singer says. “The hardest part though is that when you are singing for a film instead of your own album, you really have to ace the nuances of the emotion behind every lyric and every note and match it to how the character will be portraying it on screen. That was a learning experience.”

Lyle’s pal Josh also tries to teach his unhappy neighbors a lesson: that Lyle the singing crocodile doesn’t pose a threat. “He wears a scarf and he can sing,” Fegley remarks as Josh in the trailer.

Mendes hopes to share the inspiring movie with his loved ones and potential future kids.

“This film is so exciting because it really feels like it is for everyone, whether it’s my kids one day, or my family and friends now, I’m just so happy to be part of something that has such a positive message and that allowed me to express my musicianship through film,” he says.

Lyle, Lyle Crocodile, also starring Javier Bardem, Brett Gelman and Scoot McNairy, marks Mendes’s feature film debt — and it inspired the Grammy nominee to think about doing some on-screen acting in the future.

“I’ve been thinking quite a bit about it and just always have wanted to wait for the right role and the right time where I can focus on it creatively,” Mendes says. “I’m a huge Richard Curtis fan so maybe something like that, but who knows?”

Lyle, Lyle, Crocodile opens in theaters Oct. 7.