premise: Grease was not a film.
hypothesis: Grease is a 1978 American musical romantic comedy film based on Jim Jacobs and Warren Casey 's musical of the same name . The film depicts the life of Rydell High School students Danny Zuko and Sandy Olsson in the late 1950s . Directed by Randal Kleiser and written by Bronte Woodard , the film stars John Travolta as Danny , Olivia Newton-John as Sandy and Stockard Channing as Betty Rizzo . Grease was successful both critically and commercially . A sequel , Grease 2 , was released in 1982 , starring Maxwell Caulfield and Michelle Pfeiffer .