The best way to describe the score and sound design for "Sicario" is "dynamic realism" because of the calculated way in which director Denis Villeneuve sucks the viewer in, then slightly unnerves us with subliminal low-end bass before assaulting us with percussive hits.
Take the opening FBI SWAT raid in Arizona: "You’re introducing characters [especially the agent played by Emily Blunt] and seemingly in a safe environment and then you start to seed in sound textures that produce anxiety," recounted sound editor Alan Robert Murray. "And they let you off the hook and hit you with the shocking timpani hit [from Jóhann Jóhannsson’s score].
"It’s a quiet suburban neighborhood where the insects sound somewhat irritating. Then you jump into the tank, which has a foreboding atmosphere and then the motor winds up and it’s got almost a dentist’s drill sound to it. Then it’s quiet inside the house until the agents come crashing through the walls."
This sonic strategy continues throughout the movie, keying in on different characteristics for Blunt, the newbie, and Benicio del Toro’s mysterious hit man. Blunt’s loneliness is emphasized with isolated undertones, while del Toro’s rattlesnake surprise utilizes a more layered set of undertones.
"We went with a visceral, concussive, dynamic, silenced shot for his gun," Murray explained. "It was over the top but was still in the realm of reality."
For the memorable underground tunnel sequence, where gunshots are often off-camera, they still needed the right reverberation along with an increasing sense of concussive menace.
This dynamic realism carried over into the percussive score by Jóhannsson, who also concentrated on the low-end of the spectrum with lots of bass. "Denis suggested the notion of beating war drums since ‘Sicario’ has elements of a war film as well as a western," the composer suggested. "And the vocals have more of a subtle impact, provided by my friend Robert Aiki Aubrey Lowe.
"The first scene that I concentrated on was where the agents are driving in a convoy from El Paso to Juarez. It’s quite a long scene and I wrote a few pieces for the scene and the one that Denis latched onto had a simple but profound bass line. This very strong percussive loop transforms into a very aggressive sound. And you have the sound of the helicopter blade slowly crescendoing with the music, and I think that influenced the music later on in the film."
Utilizing a 55-piece orchestra, Jóhannsson relied on strings, brass, and woodwind for textural moods. There’s also a lot of solo cello and multi-track cello (from another friend, Hildur Guonadottir), as well as six-string bass guitar on one of his favorite cues, "Melancholia," which plays during the closing credits.
As usual, Jóhannsson took acoustic recordings that were processed electronically but with sparing use of synthesizers. The result here sounds reminiscent of David Bowie’s landmark "Heroes" instrumental work in collaboration with Brian Eno.
"I visited the set in New Mexico and absorbed the atmosphere of the desert, which is an environment I had never been in before," admitted the Icelandic composer. "It’s a strong thing to be in this beautiful, barren part of the world."