May 5, 1962 - The West Side Story soundtrack went to No.1 on the US album chart. All music by Leonard Bernstein and lyrics by Stephen Sondheim. It spent 54 weeks at No.1, 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'sWest 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.
In her autobiography, Marni Nixon spoke of singing the role of Maria and of her observations of the other singers whose voices were dubbed into the film. According to Nixon, very little of the singing on the soundtrack was contributed by the on-screen top-billing stars of the film; while George Chakiris provided vocals for the character of Bernardo, Nixon claims, even Russ Tamblyn's voice was dubbed over by Tucker Smith because Tamblyn (who played Riff) had contractual obligations with MGM Records. While the film was released by United Artists, the soundtrack album was produced by Columbia Records. Final determination of which voices would be used and how much for the film's songs was left to producer Saul Chaplin, who told Nixon that her voice would be used to supplement or extend that of actress Natalie Wood or to replace it altogether. After filming was complete, Nixon recorded several songs while watching film loops so that she could synchronize her voice to Wood's action. Nixon also dubbed several lines for Wood and contributed co-dubber Betty Wand's part to the song now called "Tonight". Although not industry standard at the time, Nixon arranged to receive a small percentage of the royalties for sales of the soundtrack, which, as she did not receive credit for her performance on the album, she indicates helped "salve any wounds".