What is Contra Dancing?
Contra dancing is cued dancing, done to a caller's instructions and live music, in which pairs of dancers repeat a sequence of steps successively with new pairs of dancers, moving down a line of couples until they reach the end. They then wait out one repeat of the music before re-entering the dance as a couple heading in the other direction, repeating the steps again until the dance ends.
Well, that's a technical definition.
Contra dancing is also a very aerobic form of dancing where you successively swing 'round and 'round with a series of dancers, gazing deeply into their eyes, and then go home all tired, sweaty, and happy.
Or, as a dancer once described a contra dance's steps to me:
Neighbor swing!
blah, blah, blah...
Partner swing!
blah, blah, blah...
and so on.
Here are some links if you want to investigate this further: