You have to start with the notion that you pick the actor who's going to embody the role, the best person that you can find. If you don't start with that then it sort of defies the whole purpose of trying to make the best film that you can make.

Being branded to some subset of your fans is important when it comes to creating films and characters they're not familiar with. It's enormously difficult to market to a global audience, and it's becoming more difficult. A brand matters to parents, whereas kids are largely driven by their urgent reaction to the product. In the future, where there are going to be choices that have to be made by parents because it will be prohibitively expensive to access everything, those will be driven partially by brand.

When you listen to the music in this film [Despicable Me], it's working on the level of melody, but the other key element is lyrics. There are a number of songs in the film where the lyrics themselves are very much speaking to the essence of what Ted Geisel was setting out to do.

Tone is an interesting question because part of the inspiration of looking to song is that Geisel himself - when you think about his animated version of The Grinch - embraced the idea of using songs in unconventional ways, as part of conveying a narrative. The use of music, in this film, is very unconventional, which I love.

The idea right now - and it may evolve - would be a live-action movie where some of his characters would be animated. To me, this movie is very much about the creative process.

There are countless times where you're trying to channel somebody who's not there, but that's what you have to do. But Audrey Geisel, who has executive produced this film and Horton, and who works remarkably close with me, is a great source of information. (The Simpsons creator) Matt Groening once told me that one of the most important roles that he fulfills on The Simpsons is being the keeper of the integrity of the original vision.

I take his [Theodore Geisel] legacy very, very seriously. I know others may disagree because he's made such an impact on so many people that response to work becomes very personal, so people will have different points of view. But, at the core of this, I take the protection and the extension of his legacy very, very seriously. It's a very important part of my life.