http://home.stny.rr.com/peverett/gadget.html

Literal:
Hayden Duet concertinas are simple, logical, and easy to learn. They are reputed to excel for playing by ear, chording behind a melody, and accompanying singing.

They’re also rare. Around 100 exist, so used Haydens just don’t come along. New instruments cost thousands of dollars, and even at those prices the waiting time stretches to years. Wanting to try one anyway, I researched concertina building — but only for a couple of hours. It took just that long to see that such a project (valves, reeds, bellows…) is WAY beyond my ambition. [more…]