Songfacts®:

• "Make 'Em Laugh" is performed by Donald O'Connor in the classic Singin' In The Rain. Although Gene Kelly was the star of this film, O'Connor was an incredibly gifted performer and arguably as good a dancer as Kelly. After first playing a bit of introductory piano, he dances and otherwise meanders his way through this number aided by a series of props, including a dummy.
  
  "Make 'Em Laugh" was written for the 1952 musical by Nacio Herb Brown and Arthur Freed, but any similarity with the Cole Porter track "Be A Clown" is not coincidental.
• Although Arthur Freed (1894-1973) was a lyricist, he was best known as a producer, and produced many, many musicals in the 1940s and 1950s. By the time the film was ready for shooting, they had no song for O'Connor's character to perform solo, so co-director Stanley Donen suggested that Brown and Freed write a new song, indicating it should be like "Be A Clown."
  
  The result was called 100% plagiarism by Donen, but although Porter could have sued, he owed a personal debt to Freed for commissioning him to write the score for The Pirate after two of his musicals had flopped consecutively on Broadway. >>>

  Suggestion credit:
  Alexander Baron - London, England, for above 2