Some fans of Sha Na Na can trace the 1950s tribute act back to Woodstock, when it preceded Jimi Hendrix onstage the final morning of the festival.
Others best remember the group of greasers from their self-titled 1977-'81 television variety series.
But the band's longtime pianist, Screamin' Scott Simon, says Sha Na Na's performance Friday night at the Wild Rose Casino and Resort in Clinton will lean heavily on the 1978 movie in which they make a brief, but memorable, appearance.
"We know a certain number of people only know us from 'Grease,' " Simon said in a phone interview from Los Angeles.
In the movie, Sha Na Na appears as the band Johnny Casino and the Gamblers, playing "Hound Dog," "Born to Hand Jive" and "Tears on My Pillow" at the Rydell High School dance.
"We barely appear as a performing band. We're just an afterthought. We were just there for them to choreograph to," Simon recalled. "But it's fine. We got six cuts on the second-largest-selling album in the history of recorded music, over 40 million sold."
But Simon also got some work behind the scenes of the John Travolta-Olivia Newton-John musical. When songs were added to the Broadway stage version, including "Hopelessly Devoted to You" by Newton-John and "You're the One That I Want," a duet for the two stars, Travolta was left without a solo.
Travolta, whose stage debut came in "Grease," Simon said, "knew the score, literally, of the musical."
So Simon wrote the verses and producer Louis St. Louis the chorus for "Sandy," Travolta's drive-in lament in the film.
The 66-year-old Simon joined Sha Na Na shortly after the band's Woodstock appearance and is one of three veterans of more than four decades with the band.
More than 50 performers have been with Sha Na Na, which started as a glee club group called the Kingsmen at Columbia University.
"We kept sifting through people who fell away for whatever reason ... but we're always on the lookout for the next guitar player because we're not really a guitar band," Simon said.
Simon said that he and the other greasers in the group have no intention of retiring anytime soon and will someday hand over the reins.
"Rock 'n' roll will keep you young," he said. "The group is bigger than anybody in it."