Several years ago I wrote a series of posts about simple contra dance piano playing: 1, 2, 3. Since then I've played a lot more piano for dancing, and rereading those posts the main thing that jumps out at me is that the style I'm showing there is based around playing left hand bass notes on the downbeat and right hand chords on the upbeat ("boom-chuck"). This is a style that many people teach to people who are completely new to playing dances, but I no longer think is a good starting point. Instead if I were writing those posts now I would start with rocking octaves on the left hand.