Question: The American soprano that sang in "West Side Story" dubbed for who in a 1956 film adaptation?

Context articles: West Side Story (Oscar Peterson Trio album)
Cal Tjader Plays Harold Arlen
Alan Johnson (choreographer)
West Side Story (Cal Tjader album)
West Side Story (soundtrack)
Deaf Side Story
Marni Nixon
Kenton's West Side Story
Getting to Know You (song)
Karen Olivo

West Side Story is a 1962 studio album by the Oscar Peterson and his trio.
 The album features jazz interpretations of seven songs from the film "West Side Story".
Cal Tjader Plays Harold Arlen is an album by American vibraphonist Cal Tjader, five of its 11 tracks arranged by Tjader's longtime colleague Clare Fischer.
 Recorded in June 1960 and released in February 1962 on the Fantasy label, it would be reissued on CD – together with Tjader's similarly semi-orchestral 1961 LP, "West Side Story" (by which time Fischer had become Tjader's full-time pianist and musical director) – on July 30, 2002, as "Cal Tjader Plays Harold Arlen and West Side Story."
Alan Johnson (Ridley Park, PA) is an award-winning choreographer, best known for his work on Mel Brooks films and for restaging Jerome Robbins original choreography in live productions of "West Side Story" in the United States and internationally.
 Johnson has been linked to "West Side Story" since making his Broadway debut in the show in 1957.
 Johnson brought the "West Side Story" dance style into the mainstream when he choreographed several Gap commercials in 2000.
 This commercial earned him an American Choreography award.
 Along with the GAP/WestSide advert, Alan also choreographed commercials for Dubonnet and Freixenet Champagne.
 He has worked with such performers as Shirley MacLaine, Leslie Uggams, Bernadette Peters, Tommy Tune, Chita Rivera and Ann-Margret.
 He is a three-time Emmy winner.
West Side Story is an album featuring American vibraphonist Cal Tjader, consisting of musical numbers from Leonard Bernstein's "West Side Story" in jazz arrangements, by Tjader's pianist and musical director Clare Fischer, without vocals.
 It was recorded in October 1960 and released on the Fantasy label in January 1961 as Fantasy 3310 / 8054 (reissued on LP in 1968, in stereo only, as Fantasy 8379).
 On July 30, 2002, Fantasy would reissue it – along with the 1962 LP "Cal Tjader Plays Harold Arlen" – on CD as "Cal Tjader Plays Harold Arlen and West Side Story".
West Side Story is the soundtrack to the 1961 film "West Side Story".
 Released in 1961, the soundtrack spent 54 weeks at No. 1 on Billboard's album charts, giving it the longest run at No. 1 of any album in history, although some lists instead credit Michael Jackson's "Thriller", on the grounds that "West Side Story" was listed on a chart for stereo albums only at a time when many albums were recorded in mono.
 In 1962, it won a Grammy award for "Best Sound Track Album – Original Cast" and Johnny Richards orchestrations of the movie score (on "Kenton's West Side Story") also winning a Grammy in 1962 for "Best Large Ensemble Jazz Album" further bolstering the popularity of the movie and soundtrack.
 In the United States, it was the best-selling album of the 1960s, certifying three times platinum by the RIAA on November 21, 1986.
Deaf Side Story is a musical based on "West Side Story", itself an adaptation of William Shakespeare's play "Romeo and Juliet".
 Takes place in New York City during the mid-1950s, the musical based on West Side Story explores the rivalry between the two gangs Jets and the Sharks, two teenage street gangs of different cultural backgrounds (Deaf and Hearing).
 The members of the Sharks from Puerto Rico are taunted by the Jets, a white working-class group.
 The young protagonist, Tony, one of the Jets, falls in love with Maria, the sister of Bernardo, the leader of the Sharks.
 The theme, music, and dances focus on culture problems.
Margaret Nixon McEathron (February 22, 1930 – July 24, 2016), known professionally as Marni Nixon, was an American soprano and playback singer for featured actresses in movie musicals.
 She was best known for dubbing the singing voices of the leading actresses in films, including "The King and I", "West Side Story", and "My Fair Lady".
Kenton's West Side Story is an album by Stan Kenton that won the Grammy Award in 1962 for Best Jazz Performance – Large Group (Instrumental).
 The album was recorded in 1961 and released quickly to take advantage of the movie premiere of the musical "West Side Story".
 Kenton won his first Grammy Award.
 He won again the next year in the same category.
 "Kenton's West Side Story" peaked at No. 16 on the "Billboard" magazine album chart.
"Getting to Know You" is a show tune from the 1951 Rodgers and Hammerstein musical "The King and I".
 It was first sung by Gertrude Lawrence in the original Broadway production and later by Marni Nixon who dubbed for Deborah Kerr in the 1956 film adaptation.
 In the show, Anna, a British schoolteacher who has been hired as a governess, sings the song as she strikes up a warm and affectionate relationship with the children and the wives of the King of Siam.
Karen Olivo (born August 7, 1976) is an American stage and television actress, who is known for originating the role of Vanessa in the Tony Award–winning musical "In the Heights" both on and off Broadway.
 She won the Tony Award for Best Featured Actress in a Musical for her performance as Anita (2009–2010) in the revival of "West Side Story".
 She is the first and only actor to win a Tony for a performance in "West Side Story.