Scoring 'The Long Walk' was an 'Automatic' yes for The Lumineers' Jeremiah Fraites

The Lumineers are currently on tour in support of their latest album, Automatic, but the band's Jeremiah Fraites is also celebrating his side project: He wrote the score for the movie The Long Walk, in theaters now.

Back in 2013, The Lumineers contributed a track called "Gale Song" to the soundtrack of The Hunger Games: Catching Fire. Fraites tells ABC Audio that connection inspired him to immediately say yes to The Long Walk, from the same director, Francis Lawrence.

The other thing that made him say yes? The Long Walk is based on a Stephen King novel. The story concerns a deadly contest in a dystopian America in which 100 young men start walking and are executed if their speed falls below a certain number of miles per hour. The last man standing is the winner.

Fraites chose to use piano and strings for the score because he needed to depict the young men's horrific situation, but also the close relationship that develops between them.

"Piano and strings can be very beautiful-sounding instruments. They can also be very terrifying-sounding instruments," he tells ABC Audio.

He adds, "I wanted to service the sort of dark aspects of what you'd expect in a Stephen King-type novel. But Francis said there's gonna be ... these intimate relationships being formed in this very cruel dystopian universe that they're living in."

Fraites says it was "a very emotional experience" to see the completed film, and he can't wait to do more.

"I'm totally hooked. I mean, honestly, it was one of the most just thrilling and really unique things that I'd ever done creatively," he says. "I'm 39. I've been wanting to score films since I was 17. ... I think this late into my life creatively, I think it was the right time."