Everyone loves to sing along with their favorite characters when they have a song in a movie. Whether it's Zac Efron in High School Musical or Rebecca Ferguson in The Greatest Showman, we not only ...

Kerr's Anna in The King and I (1956), Natalie's Maria in West Side Story (1961), and Audrey's Eliza in My Fair Lady (1964) were all dubbed by the amazing Marni Nixon, and nowhere in the credits ...

Audrey Hepburn usurped the role, even though her singing voice was dubbed by Marni Nixon for the 1964 film. (Don't weep for Andrews -- it left her free to play, and win an Oscar for, "Mary Poppins.") ...

In 1964, it was famously brought to the big screen by Audrey Hepburn and Rex Harrison, (although soprano Marni Nixon was brought in to dub Hepburn’s singing voice).

Nixon dubbed the voices for Deborah Kerr in The King and I, Natalie Wood in West Side Story and Audrey Hepburn in My Fair Lady -- three of Hollywood's biggest movie musicals.

Movie musicals My Fair Lady, On the Town, and Disney's Cinderella are among the 25 films selected by the Library of Congress to join the National Film Registry for 2018.

SIEGEL: Call it Hollywood magic or a Hollywood workaround, Nixon was usually not credited for her work. In "My Fair Lady," audiences heard Nixon's voice as Audrey Hepburn launched into song.

Nixon, who died on Sunday, was a classically trained actress who mostly worked behind the scenes. She dubbed vocals for many films, including My Fair Lady. Originally broadcast in 2001.