Actor George Clooney has vowed never to be caught on the stage of a karaoke bar - because the movie star insists he's a terrible singer. The 46-year-old admits moviemakers the Coen brothers were right to dub his singing voice in O Brother, Where Art Thou? - because he's tone deaf. And, although he's more than happy to make a fool of himself for laughs, he'd never stoop to humiliate himself by singing. He explains, "You could pull my mother out and hold a gun to her head and say you're gonna shoot her if I don't get up and sing, and I'll go, 'Shoot away, I'm not getting up there!' "I'm not a particularly good singer and I'm certainly not getting up at a bar and singing. What a frightening thought that would be."