Many a piper in a session wouldn't dream of using the regs. I did say there were no rules, Dick. However, the heart and soul in Irish instrumental music is the tune. I'm sure you play lovely harmonies on your concertina, and I love lovely harmonies, and I have many CDs by Irish bands. I even made one meself. But I also love unadorned tune-playing on single-note instruments. No rules, no either-or. Whatever girds yer loins.