I play a Maccann. There are some great players out there. I once heard a lady in UK called (I think) Lesley Henecker. And there is a brilliant American guy called David Cornell.

The duet was originally conceived as playing a tune at one end and a countertune at the other, hence 'duet'. I've never played it like that, too difficult. I use the left hand end for chords, or bass-chord-bass-chord like an accordion, plus the odd bass run. The other end plays the tune, with such extra notes as I can chuck in. Suits me.