Background: Gigi [ZiZi] is a 1958 American musical-romance film directed by Vincente Minnelli processed using MGM's Metrocolor. The screenplay by Alan Jay Lerner is based on the 1944 novella of the same name by Colette. The film features songs with lyrics by Lerner and music by Frederick Loewe, arranged and conducted by Andre Previn. In 1991, Gigi was selected for preservation in the United States National Film Registry by the Library of Congress as being "culturally, historically, or aesthetically significant".
Context: Hollywood producer Arthur Freed first proposed a musicalization of the Colette novella to Alan Jay Lerner during the Philadelphia tryout of My Fair Lady in 1954. When Lerner arrived in Hollywood two years later, Freed was battling the Hays Code to bring his tale of a courtesan-in-training to the screen. Another roadblock to the project was the fact Colette's widower had sold the rights to her novella to Gilbert Miller, who planned to produce a film version of the 1954 stage adaptation by Anita Loos. It cost Freed more than $87,000 to purchase the rights from Miller and Loos.  Lerner's songwriting partner Frederick Loewe had expressed no interest in working in Hollywood, so Lerner agreed to write the screenplay only. He and Freed discussed casting; Lerner favored Audrey Hepburn, who had starred in the Broadway production written by Loos, but Freed preferred Leslie Caron, who had co-starred in An American in Paris for him. Both agreed Maurice Chevalier would be ideal for aging boulevardier Honore Lachaille, and Lerner proposed Dirk Bogarde for Gaston. Lerner agreed to write the lyrics if Freed could convince Bogarde and designer Cecil Beaton to join the project. He decided to approach Loewe once again, and when he suggested they compose the score in Paris, Loewe agreed.  In March 1957, the duo began working in Paris. When Chevalier, who already had agreed to appear in the film, first heard "Thank Heaven for Little Girls", he was delighted. When he discussed his waning interest in wine and women in favor of performing for an audience in cabarets, Chevalier inadvertently inspired the creation of another tune for his character, "I'm Glad I'm Not Young Anymore". The lyrics for another of his songs, the duet "I Remember It Well", performed with Hermione Gingold as his former love Madame Alvarez, were adapted from words Lerner had written for Love Life, a 1948 collaboration with Kurt Weill. "Say a Prayer for Me Tonight", a solo performed by Gigi, had been written for Eliza Doolittle in My Fair Lady but was removed during the pre-Broadway run. Lerner disliked the melody, but Loewe, Freed, and Minnelli voted to include it in the film.
Question: what year was Gigi released?

Answer:
In March 1957, the duo began working in Paris.