Audry Hepburn did a wonderful job as Eliza Doolitle in the movie My Fair Lady that came out in 1964, yet fewer of us know that Marnie Nixon opened that show on Broadway as Eliza in 1956, originating that role which many of us recognize today. Shocking as it is, Audry Hepburn did not sing in the movie My Fair Lady. Marnie Nixon sang these songs and beautifully, though many of us may not recognize this.
She also sang behind the scenes for Natalie Wood in West Side Story, Deborah Kurr in The King and I, even Marilyn Monroe in Diamonds are a Girls Best Friend from Gentlemen Prefer Blondes, and many more.
