Tying up Loose Ends: It all starts with a book

Earlier this year I picked up a few novels at a church rummage sale, including one by Annie Proulx. Having enjoyed her novel, The Shipping News , I looked forward to reading this one titled Accordion Crimes. Here is a bit about the book:

The protagonist of the novel and, significantly, the character that survives longest is an accordion, crafted in Sicily and brought to the United States by its maker. When he is killed by an anti-Italian mob, the accordion passes to a black Louisianian, who is also murdered, then to a German immigrant who has settled in Iowa. Later it goes to Texas, to Maine, back to Louisiana, then to Chicago, Illinois, and to Montana.

It's a good story, actually a series of stories all involving an accordion...Not nearly as good as The Shipping News, but good.
Thinking about this accordion, I thought about what I know or how little I know about the instrument. Accordion, button box, concertina, all synonymous? I still wonder, anyone out there know?
Growing up in Wisconsin, I heard a lot of polkas, accordions are a required element. Mostly, I think of the big piano accordion, the kind with a keyboard..

I remember a couple of small accordions in the attic of my home as a child. They

belong to my Dad, who grew up in that same house. I visited him today and he told me that he played the accordion in his Grandpa's bar as a boy. His uncles played and sang to entertain the customers.