Greg, I think that last point is most telling.

Many current bands playing for social dancing in the folk world are looking backwards. Nowt wrong with that either, much good and exciting music played years ago.

But I suspect that musicians playing social dance music and looking forward will always have an ear for innovation. ( Why we have Whapweasel)

The invention of the melodeon and friends (Industrial Revolution times?) was a bit revolutionary was it? Bands before and after more than a bit different?