Punk rocker Iggy Pop has defended writing songs about his penis insisting it is a "perfectly natural" subject. The Stooges singer has been blasted by critics for penning tracks about his appendage on the band's latest album The Weirdness. But the star is adamant his penis has a place in music. He says, "You write about things of importance to you. And it's gotta be for real. Do I think about my dick? All the time. I got a right (to think) to sing about it. "If I thought, 'It's time to write a rock song, I'd better mention my dick,' then I wouldn't even be able to say 'dick' right. But it's nature-oriented."