Marco Beltrami's 'World War Z' Score: Pig Skulls and Emergency Sirens

The composer deconstructs his music for the Brad Pitt zombie odyssey.

For composer Marco Beltrami, World War Z’s opening scene, a chase through gridlocked Philadelphia, was the first spark of scoring inspiration for a specific reason.

“It ended cutting to the emergency broadcast signal and a black screen,” Beltrami tells The Hollywood Reporter. And with that, the U.S. Emergency Broadcast System siren became the basis for his score to the latest Brad Pitt starring vehicle, which has already earned $3.6 million in domestic box office since opening in select theaters on Thursday, June 20. It's eyeing a $21 million Friday putting it on track to hit between $52 million to $58 million this weekend.

How do you replicate the sound of the siren’s S.O.S. tone? The composer bought tuning forks to figure out the exact note and it turns out to be two -- doubled pitches "that are a whole step apart,” he explains. “We bought the tuning forks because it’s just a pure frequency -- nothing else.”

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Those pitches developed into the melodies and harmonies of Beltrami’s compositions, but it was the zombies’ snapping teeth that informed the score’s rhythm and percussion.

No joke -- Beltrami decided he wanted the sounds of actual teeth in the music. Tommy Lee Jones -- whose upcoming directorial effort The Homesman Beltrami is scoring -- recommended trying the javelina.

“I didn’t know what a javelina was,” Beltrami recalls of the wild pigs, found in Jones’s native Texas, which communicate with their long canine teeth. Beltrami experimented with attaching microphones to javelina skulls and clicking the jaws shut. “It’s sort of a two-phased sound,” he says. “When [the mouth] opens or closes, there’s this scraping sound as the canine teeth go together, and then there’s the actual impact when the molars hit.”

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Beltrami recorded with javelina, lion, and raccoon skulls, the latter of which he “attached to sticks and then used them almost like shakers,” he says, adding that the orchestral percussion also draws from these bony rhythms.

The music was recorded with two ensembles, a full orchestra in Abbey Road and a smaller group at British Grove studios. Says Beltrami: “There were two lines of thinking: one being that, yeah, this is a big summer blockbuster movie, and the score needs to be big epic to accompany it. But simultaneously, there was also this idea of it being a more gritty, rosin-on-the-bow, chamber-like ensemble, so that it could provide some of the up-close intensity and the intimacy.”

Beltrami credits his process -- skulls, sirens and all -- to his composing idol, Ennio Morricone.

“He would take sounds that really were not traditional orchestral sounds -- grunts, or somebody whistling, or the ticking of a clock -- and incorporate those things into, as musical elements in a score,” Beltrami says. “That’s one of the things I love about film scoring.”

Twitter: @THRMusic