Back in 1960, Greek actress Melina Mercouri starred in the movie, Never on Sunday, which was a big hit and breakthrough role for her. She received an Oscar nomination for Best Actress, and her husband Jules Dassin got nominations for both screenplay and direction. And it won the Oscar for its famous and wildly popular title song.
(Side note. If you don't know her work well -- or at all -- in 1964, Mercouri starred in another very popular film, the classic caper movie, Topkapi, which Dassin also wrote and directed.)
Seven years later, in 1967, Never On Sunday got adapted as a Broadway musical, titled Illya Darling. What made it notable is that Melina Mercouri recreated her starring role for the show, and was far-and-away the big draw. But all the pedigree was pretty good. Jules Dassin adapted his own book and directed. The music was once again written by Manos Hadjidakis who had done the score for the movie (and won the Oscar with the title song), and it had lyrics by Joe Darion who two years early did the show, Man of La Mancha, The musical didn't have a long run, though a respectable one of 320 performance, about 10 months, largely on the strength of Mercouri, who got a Tony nomination as Best Actress in a Musical. In all the show received six Tony nomination, including Best Musical and Best Score.
Here's 11 minutes of llya Darling when it appeared on the Sunday night Ed Sullivan Show. It begins with a solo number by Melina Mercouri (a bit surprisingly pre-recorded). Then there's a major production number which is the somehat off-beat part, because it's long and while the chorus and others sing in it, Mercouri doesn't sing a word. However, she does join in the lively dancing. And though that's not her top skill, she and everyone is very enthusiastic. And then finally, just because no doubt the audience is expecting it (as is every audience seeing the show), they toss in a bit of the famous "Never on Sunday" song, which was interpolated into the musical.