Since so much effort was put into the realism of the space scenes in "Gravity," the filmmakers didn't want to ruin them with a typical Hollywood soundtrack.
Director Alfonso Cuaron said composer Steven Price eschewed the usual left-right stereo speaker sound for something more immersive.
"Steve designed the music to come from all parts of the room," Cuaron said.
Additionally, the soundtrack has no percussions, which Cuaron said have "now become a cliche of action movies. It would have sounded like we were cheating in space."