It's a subject that Burtt has devoted a lot of thought to over the years, this idea of going back and changing a text once it's ostensibly completed. "Initially I thought that when films are done you should just leave them alone. Even if there's flaws in it, they're a product of a certain creative process in their day."
"That's how I felt after we finished the first three films," he explains. "But the world has changed. As I say, George has never wanted to let them sit still. He's always had additional thoughts because I think he enjoys it."