Dancing socially can be a lot of fun, but most kinds have really
brutal learning curves. With a formalized partner dance such as swing
or tango you need to take lessons before you're ready to dance with
people at an evening, and then you'll need to take more lessons before
you're any good at it. "As a very rough guide a man will take about 3
months to be able to dance [tango], and a year to start dancing
semi-competently; a woman will take about half the time." (a tango
faq) At the other end, with nominally unstructured dancing like
you might find at a club, there are lots of skills but you're expected
to pick them up from the dancers around you. While staying original
and true to your inner style, of course. Both of these approaches can
be frustrating: lessons aren't much fun, but if there aren't lessons
how do you learn what to do?
Contra dance takes a different approach. In an evening you do a many
individual dances, and before each one there is a mini-lesson where a
caller takes a minute or two and briefly teaches the dance. This is
just enough instruction that even people who just walked in off the
street can have fun doing it, supported by the experienced dancers.
This makes it really easy to get started.
As you move from a beginner to an intermediate dancer you start to see
how that dance as taught is a framework that you can build on and play
with. This lets contra be simultaneously approachable and deep enough
to hold interest for years. It looks something like this: