Messe, who also plays accordion and glockenspiel for Hem, told Paste.com he's been a longstanding fan of the 2001 French film starring Audrey Tautou and Mathieu Kassovitz.
He said he had already written a song -- "Half Asleep" -- for Hem inspired by a scene in the movie.
"I wrote that imagining that scene where Amélie and Nino are speaking between the door," he said. "So I'd already written a song for those characters, but then it took years and years to get the rights."
Messe said he doesn't plan to simply mimic the style of the Yann Tiersen score from the film.
"It's like one of the best movie scores there is. It's one of the reasons why I love the film," he said. "But, it's not what I do. He's a very different sort of composer than I am. And I'm not interested in doing Parisian music. I don't think I'm even going to use accordion in my score. The music sounds like mine. But certainly, I'm not playing up the Americana elements either. I'm not having pedal steel and fiddle, but it'll be hyper-romantic and playful more than anything."