Here is Rydell High’s senior class of 1959: duck-tailed, hot-rodding “Burger Palace Boys’ and their gum-snapping, hip-shaking “Pink Ladies” in bobby sox and pedal pushers, evoking the look and sound of the 1950s in this rollicking musical. Head “greaser” Danny Zuko and new (good) girl Sandy Dumbrowski try to relive the high romance of their “Summer Nights” as the rest of the gang sings and dances its way through such songs as “Greased Lightnin’,” “It’s Raining on Prom Night” and “Alone at the Drive-In Movie,” recalling the music of Buddy Holly, Little Richard and Elvis Presley that became the soundtrack of a generation. An eight-year run on Broadway and two subsequent revivals, along with innumerable school and community productions, place Grease among the world’s most popular musicals.