What is contra dancing? From www.childgrove.org/about_contradance.htm :
It's a communal-style folk dance that is fun and easy to learn. No partner or experience is necessary. A caller leads the dancers through a series of moves and the sequence repeats itself. The patterns are very easy to learn and it's more like walking to music. An evening consists of 10-12 dances, each with a different combination of a few simple moves. You can enjoy dancing in a friendly, fun, mostly wholesome environment.The picture below attests that the experience is for all ages and backgrounds. I really enjoy this style of dance and encourage everyone to try it out.