What year is 'Little Shop of Horrors' set in?

I got the part of a singing girl (which is Crystal, Ronette and Chiffon, but theres five of us so we're all called singing girls) and the show is in a couple of weeks and I want to know what year it's set in so I could style my hair as it was back then. And if it's possible can you send me some pictures of the hairstyles they had that year. Thank you for your time :)