Flapper Julie Andrews

The Boy Friend. Music, Lyrics and Book by Sandy Wilson. 1953 West End. 1954 Broadway

Thoroughly Modern Millie. 1967 screenplay by Richard Morris. Original music by Elmer Bernstein.  2002 book by Richard Morris. Original music by Jeanine Tesori. Original lyrics by Dick Scanlan.

The Broadway transfer of The Boyfriend featured the New York debut of Julie Andrews! She would don her flapper dresses again for Millie and make her directing debut with a production of The Boyfriend in 2003. Both stories focus on flappers who enjoy their independence till their poor boyfriends confess they are secretly rich and propose. It's telling that the sequel to The Boyfriend was titled Divorce Me, Darling!

The Boy Friend is a fairly conventional musical that was turned into a strange film.
Millie was a weird film that got turned into a conventional musical. Carol Channing and Beatrice Lillie are doing... something... bizarre that the raise the film to new camp levels. Channing's character was toned down when the show transferred to Broadway but Harriet Harris made Lillie's villain her own crazy (and Tony winning) creation.

Trailer for The Boy Friend on film.
Trailer for Thoroughly Modern Millie on film.
Performance from Thoroughly Modern Millie at the Tony's.

Breakfast at Tiffany's

Burrows gave audiences the standard musical comedy treatment in Philadelphia. Audiences snored. Albee  restored the darkness of the source material in Boston. Audiences booed and producer David Merrick shut it all down. The scandal lifted the show to mythical flop status. When the score was  given a recording people were disappointed. We were expecting insanity and got mediocrity.

Edward Albee: "They made a perfectly safe, middlebrow, mediocre and, I thought, extremely boring musical that would have probably run a year on Broadway. I managed to turn it into a disaster that never opened on Broadway.”

A similar thing happened to the Richard Greenberg play in 2013. Truman Capote's stories are better remembered for atmosphere than plot. The film Breakfast at Tiffany's rewrote the story considerably but is remembered for Audrey Hepburn and Moon River. A stage adaptation has neither of those to draw from.