luk. our chris connelly asked him for his secret. ♪ hey over there >> reporter: "hold it against me," the newest video from britney spears. it had its world premiere on mtv just hours ago. ♪ play my favorite song here at conway studios in hollywood, he is one of the principal architects of that song. that little tented area, that's where you record vocals, is that the idea? >> yep, that's where today britney would be. she sounds good fast, you know? she's a lot busier than i am so she comes in and gets it done and she's out. >> reporter: with 21 number one singles to his credit, he is 37-year-old producer and songwriter lukasz gottwald, the man everyone calls dr. luk, the most successful and sought after hitmaker in pop music today. ♪ here i am ♪ once again ♪ i'm torn into pieces >> reporter: he shaped the "american idol" kelly clarkson. ♪ california girl >> reporter: katy perry's candy coated confection. ♪ trying to get a little bit tipsy ♪ >> reporter: and the too many martinis tipsy doo