Soprano Marni Nixon, now 78 years old, has one of the most recognizable voices in the movies...but you probably don't know her name or her face.

That's because Marni Nixon was the singing voice behind well-known actresses in West Side Story, The King and I, My Fair Lady, and many other films. She had a singing career of her own, but she became indispensable in Hollywood for dubbing in songs for leading ladies including Audrey Hepburn, Deborah Kerr, Natalie Wood, Jeanne Crain, and Marilyn Monroe. (You can find a Marni Nixon biography here.)

Her prowess at being a "ghost" singer led to her nicknames "The Ghostess with the Mostess" and "The Voice of Hollywood."