All of the artists that I've worked with have an incredible work ethic. And Madonna has the best work ethic of them all. I've learned a lot from being around her.

There is a definite Chinese pop sound developing, but I was shocked at how influenced it is by American music.

Madonna has a very unique style and comes up constantly with these great songs.

Let their music skill speak for [itself]. If they are producing good tracks and are resonating with their fans, or even gaining new fans, then that's great.

U2 and folks like that. They all have that similar drive and that belief in themselves. They're early birds ... they're up working when everyone else is sleeping. They're simply all great at what they do.

I've been going to China every year now for more than a decade.

When I was in the studio with Madonna, we would work 12-hour days. If you want to work with the best, then that's what you have to do.