In an interview with USA Today, frontman for Nine Inch Nails and film composer Trent Reznor explained how the haunting, evocative music for the new David Fincher film Gone Girl came to be.

“So here’s what happened. David was at the chiropractor and heard this music that was inauthentically trying to make him feel OK, and that became a perfect metaphor for this film,” explained Reznor. “The challenge was simply, what is the musical equivalent of the same sort of façade of comfort and a feeling of insincerity that that music represented?”

The result is more of a soundscape than a typical film score using traditional instruments. Although Reznor and longtime collaborator Atticus Ross utilized guitars, drums, and keyboards, the duo fashioned their own unique instruments as well, designed to elicit just the right sound that could not be made in any other way. These were used to enhance the audio palette in order to manipulate your perception of the music.

Among them, a handmade device that Reznor describes thus, “when tapped makes a weird stuttering beat. So when you use that as a foundation for a track that has a sexy background, the core is inherently broken and you sense that.”

Still, the 49 year old musician doesn’t think viewers will go to such great lengths to decode or dissect his score so closely, but start to raise some doubts about the tone and atmosphere of the film they’re viewing instead.

“I want people who go to this movie to think, ‘Hmm, there’s something wrong with what’s happening here. Why do I feel uneasy?'” said Reznor. “You’re seeing what appears to be the truth, often through rose-tinted glasses. So I’m there to instill doubt. To remind you things aren’t always what they seem to be.”

This is the third film in which Reznor has worked with Fincher, following 2010’s The Social Network, and the 2011 English remake of The Girl with the Dragon Tattoo.

He added, “I really have to hand it to David, with the whole chiropractor’s office idea. That’s something I would have never thought of, being inspired by music while your back is being realigned. But it proved to be something that really set us down a clear path for this movie.”

Gone Girl opens nationwide on October 3.