And the sound design profoundly influenced Steven Price’s eerie score as well. "We worked very closely so that we weren't trying to do battle, Freemantle adds. "He used vibrations as well in place of percussion and we used filtered stuff, radio signals sometimes. We did it in a scientific way. Sometimes we would underscore the music with some subsonic base that you don't actually hear but you feel. The dynamics between the two makes it more exciting."

Price says the music needed to have an expanded role in keeping with sounds coming through vibrations. And Cuaron wanted to express sounds through tonal means as well as through music, so the sound became part of the composing process. The director also insisted that there be no percussion.

"The early cues were the hardest and took the longest time," Price suggests. "How do you compose an action score when all of the conventions of action scoring have been removed and there's no sound to compete with? We did a lot of experimentation with getting that intensity and trying to get the pacing right so you're with her all the way. There's a lot of layering in the score with the idea that it's immersive. 


"The 'Debris' cue is the first time you get that and you hear all sorts of things that we recorded separately, and lots of elements I wrote to fly around you and to nudge you into her head almost. We blurred organic and electronic instrumentation so a lot of the sounds start out organically: glass harmonica, pipe organ, and textures that derive from breathing or low voices. 

"But everything was processed after recording, including the orchestral elements, which could be moved around throughout the surround speakers. I might record one line and then another so they could follow the movement of the characters. For instance, as Sandra falls, the string line would fall with her and it might meet something that was coming in. It was all designed around the choreography of the characters."

For co-editor Mark Sanger (who previously served as VFX editor on Cuaron's "Children of Men"), his impact began early. He joined the project in pre-production four years ago, helping the director build on his initial vision. They had a complete cut of the movie in animation 18 months before Bullock and George Clooney arrived, which they screened for Warner Bros., with temp sound and music, and Sanger and his assistant, Tanya Clark, standing in for the two stars. 

The camera was rarely locked to any spatial plane so it was a challenge to make the cuts work within the right geography. But the cyclical process with Cuaron and Framestore, the VFX company, allowed for changes in blocking that inevitably occurred. Sanger spent hours or days re-editing the rest of the scene to achieve the proper balance, continuity, and rhythm.

"It's not often that the editor gets to work collaboratively with all of the other guys at the very beginning of the design process in pushing the film along," Sanger admits. "For me, it was very exciting because there were decisions that we were making early on that would obviously change the script. We were all working together to get the best possible movie long before we were ever going to shoot it. 

"Once we could see how the structure of the film was coming about, then there came a point for several months where it was more of a technical process. And editorial decisions at that stage had financial implications. As an editor, you're used to dealing with financial implications in post-production where you've got visual effects shots and figuring out how many you can use within a given sequence. 

"But we were having conversations about how we were going to shoot it, and whether it was physically possible for us to deliver the actors' performances within the confines of the shots we were putting together. And so it was a unique situation, but then there came a point after about 18 months when the actors arrived and it blossomed into a creative process. And those were the times when you got a burst of enthusiasm after working on a cut with a lot of featureless previs for so long."

They certainly delivered a unique blockbuster spectacle with emotional resonance beyond anyone's expectations.