Composed by Jim Jacobs and Warren Casey in the early 1970’s for the musical Grease and then used in the film adaptation of the musical in 1978. The musical premiered in Chicago in 1971. The song was composed for the show’s transition to Broadway and was not used in Chicago, where they instead had a song called Foster Beach. Summer Nights reached No.1 in Ireland and the UK, remaining at No.1 in the UK for seven weeks. Chart-History.