Anita Spring, billed as an Olivia Newton-John tribute artist, joins Jonny Gardiner and a flamboyantly costumed band for a musical mashup of Grease and The Rocky Horror Picture Show. The show combines songs from both cult-film musicals with nostalgia, jokes and audience participation, inviting patrons to sing, dance and dress up. It specifically highlights “Summer Nights” and the “Time Warp,” with a best-dressed prize on the night.