How do I dress like the 70's/80's?

We are doing a disco medley (Boogie Fever, Dancing Queen, More Than A Woman, Staying Alive, How Deep Is Your Love, I Will Survive, We Are Family) for my chorus concert and we are supposed to dress up for that time period. What would a teenager be wearing in that era? Please keep in mind I still want to look cute and a little bit modern. Thanks!