It is quite a while since I bought (or played) my autoharp. At some point I traded my 12 chord model for a 15. On this side of the pond, Oscar Schmidt owns the word "autoharp" and is the main producer, but some of the hand made ones are lovely. Does anyone make them in Britain? At least in the 60s, there were 12 chord models and 3 different setups of 15 chord models. The most complete key in the 12 chord was F. One of the 15 chord setups included a bundh of diminished chords. I did not see any 21 models at the time. Oscar Schmidt would sell any chord bars you wanted - real cheap for the ones they put on autoharps and slightly more for other chords. Cuddling up to the autoharp with the echos in my ear is more fun than playing on my lap, IMHO. They ar eeasy to play.