My dad and his father, uncles and grandfather back in Iowa in the
1920s
and 1930s played for barn dances and according to my dad, they
used this basic concept for playing accompanyment on a piano. On
a modern electronic keyboard, a lot of this is built right in to the
system. I think it's cool, but I think it's more fun to know how
it all goes together and play the notes yourself. It will take
awhile to learn enough very basic theory to do this, but it is
fun. And there is a lot of carryover of the music theory to
playing chords on guitar or mandolin. Have fun with this stuff.