The screenplay had been written according to musical principals. There’s an audio illusion, if you will, in music called a “ Shepard tone ” and with my composer David Julyan on “The Prestige” we explored that and based a lot of the score around that. And it’s an illusion where there’s a continuing ascension of tone. It’s a corkscrew effect. It’s always going up and up and up but it never goes outside of its range. And I wrote the script according to that principle. I interwove the three timelines in such a way that there’s a continual feeling of intensity. Increasing intensity. So I wanted to build the music on similar mathematical principals.