It's Saturday night.

The second-floor ballroom over the town hall in the small Monadnock village of Fitzwilliam, N.H. is filled with dancers. It's a mixed crowd: some old folks, some young, mostly people in their mid-20s to early 50s. They are standing in couples, chatting restlessly, forming the long, double lines in which traditional New England contra dances are done. No one has announced that a contra is coming next, but then no one has to: all of these people have danced to Duke Miller before.

"I don't think Duke's changed his program in 30 years," my partner tells me. "Starts with a contra, three squares, a polka, and a break. Then the ...