George Bernard Shaw's 1913 play, Pygmalion, was adapted into a musical in 1956 by Alan Jay Lerner, called My Fair Lady. In 1964 George Cukor took My Fair Lady off Broadway and turned it into a film. He kept Rex Harrison as Henry Higgins, but he and producer Jack Warner, were afraid to use Julie Andrews as Eliza Doolittle because of her inexperience and lack of reputation in films. So he placed Audrey Hepburn in the role and had Marni Nixon dub her singing. On the whole, George Cukor's film stayed close to Shaw's original play but did have some alterations.
In Pygmalion Higgins and Pickering take Eliza to Henry's mother's house while she was expecting visitors. In My Fair Lady, they took her to his mother's (Gladys Cooper) box during the opening day at the Ascot races. By doing so, they had the same dialogue, plus some additions concerning the race, such as my favorite, Eliza's blurting out: "Come on, Dovuh, move your bloomin' ass!"
One of the biggest alterations was the musical aspect. The singing both added and took away from different aspects of the play. The musical tunes made the play more entertaining but at the same time took some of the seriousness of Pygmalion. For example when they all began singing "The Rain in Spain," it became a little corny.
My Fair Lady went into more detail than did Pygmalion of Eliza's training. I believe this helped to develop the characters and their relationships more thoroughly.
The viewers of the musical were able to see their ups and downs and the many long hours of work put into her development. This also gives the audience a better appreciation of their ultimate achievement at the end.
The endings are very different. In Pygmalion, Eliza's father runs into Higgins and Pickering in the house of Higgins' mother and complains to them about having been shoved by Higgins in the "middle-class morality." Then Mrs. Higgins and Pickering leave to get ready to attend Mr. Doolittle's edding. In My Fair Lady, Eliza runs into him on the street, where he makes a similar complaint to her. Both versions begin with Eliza leaving Professor Higgins at his mother's house; but in My Fair Lady she returns at his house, whereas, in Pygmalion she did not.
Even though Cukor's film did not do the story in its original form, I believe he improved it immensely, especially with the singing and ending. All of these changes made the story more appealing and attractive for audiences of all ages.