The Infinite Auditory Illusion That Makes the Dunkirk Soundtrack So Intense (and Good)

I remarked on Twitter recently that “Hans Zimmer’s soundtrack for Dunkirk is outstanding”. The music blends perfectly with the action on the screen without being overbearing; it’s perhaps the best marriage of sound and visuals I’ve experienced in a movie theater since Mad Max: Fury Road or even Tron: Legacy.¹

Zimmer and Dunkirk director Christopher Nolan achieved that effect by utilizing an auditory illusion called the Shepard tone, a sound that appears to infinitely rise (or fall) in pitch — the video above refers to it as “a barber’s pole of sound”. From a Business Insider interview with Nolan:

The screenplay had been written according to musical principals. There’s an audio illusion, if you will, in music called a “Shepard tone” and with my composer David Julyan on “The Prestige” we explored that and based a lot of the score around that. And it’s an illusion where there’s a continuing ascension of tone. It’s a corkscrew effect. It’s always going up and up and up but it never goes outside of its range. And I wrote the script according to that principle. I interwove the three timelines in such a way that there’s a continual feeling of intensity. Increasing intensity. So I wanted to build the music on similar mathematical principals. Very early on I sent Hans a recording that I made of a watch that I own with a particularly insistent ticking and we started to build the track out of that sound and then working from that sound we built the music as we built the picture cut. So there’s a fusion of music and sound effects and picture that we’ve never been able to achieve before.

1. I don’t know if I’ve ever mentioned this — because it fits somewhere between “unpopular opinion” and “embarrassing admission” on the scale of things one doesn’t talk about in public — but seeing Tron: Legacy in 3D IMAX was one of the top 5 movie-going experiences of my life. The Light Cycle battle was 80 feet tall and because of the 3D glasses, it looked like it extended out from the screen to immediately in front of my face, to the point where I actually reached out and tried to touch it a couple times. And all the while, Daft Punk was pounding into my brain from who knows how many speakers. I was not on drugs and hadn’t been drinking, but it was one of the most mind-altering experiences of my life. ↩

• audio
• Christopher Nolan
• Dunkirk
• Hans Zimmer
• movies
• music
• Tron Legacy
• video