[source: NME.com] Rock legend Iggy Pop insists writing about his penis is perfectly natural, because he wants to sing about "things of importance". The 60-year-old Stooges frontman and punk icon has been lambasted by critics, including his former NME writer pal Nick Kent, for writing songs about his appendage on latest album The Weirdness. Opening track "Trollin" features the lyrics: "My d**k is turning into a tree". But Pop is adamant his penis has a place in his music. "You write about things of importance to you," he told Rolling Stone magazine. "And it's gotta be for real. Do I think about my d**k? All the time. I've got a right to sing about it. "If I thought, 'It's time to write a rock song, I'd better mention my d**k', then I wouldn't even be able to say 'd**k'. But it's nature-oriented."