Entering this weekend as the No. 1 movie at the box office is 'Despicable Me,' and one of the highlights of the 3-D animated film is the musical score, which was composed by recording artist, producer, musician and fashion designer Pharrell Williams.

The Grammy Award-winning artist is making his debut in the film world from behind the scenes. "All my life I've watched cartoons; I love cartoons," said the Virginia native, who has produced hit songs by Snoop Dogg, Gwen Stefani, Beyonce, Jay-Z and Mariah Carey.

'Despicable' centers around a criminal mastermind using a trio of orphan girls as pawns for a grand scheme. He finds himself profoundly changed by the growing love between them.

We caught up to the hip-hop maestro recently. Below are excerpts from the conversation.

What's the difference between making music for whatever concept you have, producing somebody else and doing it for a movie.

PW: When you're doing it for someone else, I am mainly looking at the person, judging what they may need, trying to find the holes in the voice. And most of the time, there usually is a hole just because they'd just be wrapping up the album. So we find the hole, and instead of patching it, we try to use that hole as the inspiration to fill it and to make something different and take it to the next level.

With a song, there's usually about 10 basic structures. With a musical score, there's no structure at all. There are no parameters; you're only really answering to the aesthetic and what is being shown and what the director wants to be articulated at that moment.

How did you decided to get involved with this project?

PW: I was bugging music supervisor Kathy Nelson because she had awarded a job to Jack Johnson for 'Curious George,' and I thought he had done such an amazing job so I was like, "Man, I'd do anything for a movie." She said that she would try and would let me know when the next concept came about like that, and it did. So once it did, I just jumped in and I threw caution to the wind and I gave it everything that I could.

What were the challenges?

PW: I don't believe in challenges, I believe in lessons and just learning as much as you can. That's how I was raised in high school. We were there to learn; we didn't have time to talk about how hard it was. You either get this amazing gift called education or you sit home and complain with the bums. Seize your opportunities.

This movie is, as you say, very funny and entertaining, but it does center around a topic that's very serious -- adoption. Do you have thoughts on that?

PW: It's a very interesting concept, and I feel like if a person has the time, it's something that, in the bigger picture of humanity, would be nice for everyone who could afford to do it and who has the time and the will to educate and invest in a child. But you've got to have that time; you've got to have time to do stuff like that. You'll be robbing a child of a better experience if you don't have the time. But to each his own.

Take me through a day when you're sitting working on writing for film. What is the process like?

PW: Well, you concentrate more on where the emotion is going. I'm there to fill in the gaps between what the director is conveying, what the scene is suggesting. And there's the third element of the sound and where it helps to contour to and parallel the director's vision. That's my job mainly. -- with Brad Balfour