Grease is a 1971 musical by Jim Jacobs and Warren Casey. Named after the 1950s United States working-class youth subculture known as greasers, the musical is set in 1959 at fictional Rydell High School (based on William Howard Taft School in Chicago, Illinois) and follows ten working-class teenagers as they navigate the complexities of peer pressure, politics, personal core values, and love. The score borrows heavily from the sounds of early rock and roll. In its original production in Chicago, Grease was a raunchy, raw, aggressive, vulgar show. Subsequent productions sanitized it and tamed it down. The show mentions social issues such as teenage pregnancy, peer pressure and gang violence; its themes include love, friendship, teenage rebellion, sexual exploration during adolescence, and, to some extent, class consciousness/class conflict. Jacobs described the show's basic plot as a subversion of common tropes of 1950s cinema, since the female lead, who in many 1950s films transformed the alpha male into a more sensitive and sympathetic character, is instead drawn into the man's influence and transforms into his fantasy.
Grease was first performed in 1971 in the original Kingston Mines nightclub in Chicago (since demolished). From there, it has been successful on both stage and screen, but the content has been diluted and its teenage characters have become less Chicago habitués (the characters' Polish-American backgrounds in particular are ignored with last names often changed, although two Italian-American characters are left identifiably ethnic) and more generic. At the time that it closed in 1980, Grease's 3,388-performance run was the longest yet in Broadway history, although it was surpassed by A Chorus Line on September 29, 1983. It went on to become a West End hit, a successful feature film, two popular Broadway revivals in 1994 and 2007, and a staple of regional theatre, summer stock, community theatre, and high school and middle school drama groups. It remains Broadway's 15th longest-running show.
Grease was adapted in 1978 as a feature film also named Grease, which removed some plot elements, characters and songs while adding new songs and elaborating on some plot elements only alluded to in the musical. Some of these revisions have been incorporated into revivals of the musical (John Farrar, who wrote two of the new songs, is credited alongside Jacobs and Casey for the music in these productions).