Although Monroe did most of her own singing in Gentlemen Prefer Blondes, it was Marni Nixon who was brought in to sing the high notes in the song Diamonds are a Girls Best Friend. Natalie Wood's singing voice was actually recorded for West Side Story, but the producers recorded Nixon as well and it's her voice not Woods that audiences hear in the final picture. And that wonderful singing voice that came out of Audrey Hepburn's mouth in My Fair Lady? You guessed it.
Her first on-screen role was that of Sister Sophia in The Sound of Music, where Julie Andrews did her own singing, but not many non-singing roles followed for this gifted performer. She then returned to live theatre during the 1970's and then ended up on the small screen in 1980 as the host of the Emmy award winning children's show, Boomerang.
Hollywood typecast her as the go to person when needing a beautiful voice, but with her impressive musical theatre and opera resume, her career should have lead to more mainstream fame. The music profession knows and respects her talent and she made a pretty good career out of her musical gifts. And the fact that Marni Nixon isn't known among mainstream audiences is both a curse and a blessing for the Not Very Famous...but should be.