At the hight of the deluge last weekend, I was traipsing around western Massachusetts doing the tourist thing with my wife, brother, and cousin. So there we were at the Massachusetts Museum of Contemporary Art (MASS MoCA) in North Adams when my wife says "Did you see the concertina in the next room?"   I had already been through that room and hadn't noticed any concertinas. So she took me back in there and pointed to a spot on a huge mural that took up a whole wall, and sure enough, there it w