Hi Ridge,
The main thing I'd suggest is to not worry about going over a phrase of music -
Fail-safe ones that I've used:
Any La Bastringue-type dance - with do-si-do and either short or no swing and then promenade - lots of built-in time to finish a figure.
Visiting couple square dance - again - forget staying on the phrase - great when it happens/fine when it doesn't.
Circassion Circle
Virginia Reel (tell them they can walk, they don't have to sashay if it's not safe for them); reeling the set it optional (you can demonstrate and see if any want to try it).
Email me if you'd like a few more that I've used at senior centers.
Patricia