 According to Marni Nixon (qv), the studio initially wanted  Marilyn Monroe (qv)s entire voice dubbed, as they thought her  voice was silly. Nixon thought that was "awful", as she felt  Monroes voice suited her persona so beautifully. Nixon told The New  York Times in March 2007 that she ended up only dubbing a single  line of Monroes singing during the whole movie: the lyrics "These  rocks dont lose their shape" in the song "Diamonds are a Girls  Best Friend."