"I Could Have Danced All Night" is a song from which New York Broadway musical?

"I Could Have Danced All Night" is a song from the New York Broadway musical "My Fair Lady". This is a musical that was based on George Bernard Shaw's 1913 play "Pygmalion", with the book and lyrics by Alan Jay Lerner and music by Frederick Loewe. The story concerns Eliza Doolittle, a Cockney flower girl who takes speech lessons from professor Henry Higgins, a phonetician. She wants to fit into society as a lady. The original Broadway and London shows starred Rex Harrison and Julie Andrews. The musical's 1956 Broadway production was a notable critical and popular success. It set a record for the longest run of any show on Broadway up to that time.

The song "I Could Have Danced All Night" is included in Act I of "My Fair Lady". At one point in their dealings, Professor Higgins is about to give up on Eliza and her ability to learn. But she suddenly recites one of her diction exercises in perfect upper class style in "The Rain in Spain". Though Mrs. Pearce, the housekeeper, insists that Eliza go to bed, Eliza declares she is too excited to sleep in "I Could Have Danced All Night".