It's because the Hippodrome is hosting a Sing-a-long-a Hairspray evening, which invites fans of the movie and West End show to dress up, sing along and dance in the aisles.
There will be a fancy dress competition and more fun events before the film is screened and would-be performers can test how tuneful they are.
Hairspray features big-hearted Tracy Turnblad, who longs to be a dancer, but finds that she encounters prejudice because of her size.
John Travolta dresses in drag for the film, playing Tracy's mum Edna.
"Sing-a-long-a Hairspray is a wild, noisy, fun filled experience. Dance in the aisles, boo Velma and be amazed at John Travolta's fat suit," the website urges.
Earlier this month, Sound of Music fans in Lancaster dressed up in Naughty Nun Costumes to take part in a similar event celebrating the musical.