Contra dance is a little like square dance. Like square dance, we have a caller who prompts us through the dance. Like square dance, we dance some with our partner, then some with our neighboring dancers. In contrast with square dance, we always have a live band; we dance with 50 or more neighboring dancers since we dance in a line instead of a square (but it's not what you may think of as line dancing); no special clothing is required. The tradition is to change partners at the end of every dance. You may bring a partner (or other friends), but you'll have lots of people to dance with even if you don't.

Gary Shapiro maintains a website that explains what contra dancing is (and is not) in great detail. Click here to go there.