Question: Which ballet piece,  now one of the most popular of all ballets despite its initial failure, inspired "Somewhere" the song from the 1957 Broadway musical "West Side Story?"
Context: West Side Story Suite is a ballet made by New York City Ballet balletmaster Jerome Robbins to the 1957 music by Leonard Bernstein and lyrics of Stephen Sondheim and extracted from the eponymous musical which he had choreographed, with scenery by Oliver Smith, costumes by Irene Sharaff and lighting by Jennifer Tipton.  The premiere took place at New York State Theater on Thursday, May 18, 1995.  Nikolaj Hübbe and Jock Soto, both members of the original cast, as well as Peter Boal all chose to include "West Side Story Suite" in their farewell performances at City Ballet. "Somewhere", sometimes referred to as "Somewhere (There's a Place for Us)" or simply "There's a Place for Us", is a song from the 1957 Broadway musical "West Side Story" that was made into a film in 1961.  The music is composed by Leonard Bernstein with lyrics by Stephen Sondheim, and takes a phrase from the slow movement of Beethoven's 'Emperor' Piano Concerto, which forms the start of the melody, and also a longer phrase from the main theme of Pyotr Tchaikovsky's Swan Lake. Swan Lake (Russian: Лебединое озеро /"Lebedinoye ozero"), Op.  20, is a ballet composed by Pyotr Ilyich Tchaikovsky in 1875–76.  Despite its initial failure, it is now one of the most popular of all ballets. 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 (Original Broadway Cast) is the 1957 recording of a Broadway production of the musical "West Side Story".  Recorded 3 days after the show opened at the Winter Garden Theatre, the recording was released in October 1957 in both mono and stereo formats.  In 1962, the album reached #5 on Billboard's "Pop Album" chart.  It certified "gold" by the RIAA on January 12, 1962.  The album was reissued in 1973 and made its first appearance on CD in 1986.  A 1997 remastered edition includes nine additional tracks of Leonard Bernstein conducting the New York Philharmonic through symphonic versions of the songs at the Manhattan Center on March 6, 1961. 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. 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. West Side Story is a 1961 American musical romantic drama film directed by Robert Wise and Jerome Robbins.  The film is an adaptation of the 1957 Broadway musical of the same name, which in turn was inspired by William Shakespeare's play "Romeo and Juliet".  It stars Natalie Wood, Richard Beymer, Russ Tamblyn, Rita Moreno, and George Chakiris, and was photographed by Daniel L. Fapp, A.S.C., in Super Panavision 70.  Released on October 18, 1961 through United Artists, the film received high praise from critics and viewers, and became the second highest grossing film of the year in the United States.  The film was nominated for 11 Academy Awards and won 10, including Best Picture (as well as a special award for Robbins), becoming the record holder for the most wins for a movie musical. "A Boy Like That" is a song from the 1957 Broadway musical "West Side Story", with music by Leonard Bernstein and lyrics by Stephen Sondheim.  In the musical, the song is paired with "I Have a Love" and is sung by the characters Anita and Maria.  For the original Broadway cast recording, the song was performed by Chita Rivera (Anita) and Carol Lawrence (Maria).  In the 1960 film version the roles were played by Rita Moreno and Natalie Wood, but the songs were dubbed by Betty Wand and Marni Nixon (as both Anita and Maria).  However, the repeat of the two stanzas, sung by Anita, along with Maria's counterpoint of her defense, was omitted because of the complexity of the song, as well as to avoid the repetition, which would have slowed down the pace of the film. 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.
Answer: Swan Lake