Big question here- You might check out an article I wrote for Folkworks about the fiddle, and fiddle styles. It isn't concise (2000 words) but may give you some help in organizing your own thoughts on this (May/June issue at www.Folkworks.org

But this is part of my take on it... Fiddle tunes from England, Scotland & Ireland came to this country with immigrants who settled here in the 17th-19th centuries. Depending on where the immigrants settled, the original music underwent changes. According to Bruce Molsky and others, old-time (Appalachian) music was heavily influenced by African polyrhythms and pretty much sticks to reels. New England fiddling traditions didn't abandon jigs and didn't mess with the rhythm but dropped most of the ornamentation found in Irish/Scottish/Cape Breton music. Bluegrass was invented by Bill Monroe, the Stanley brothers and their peers, but developed directly from the old-time string band music. In the instrumental realm of bluegrass, there are tunes, such as Bill Cheatum or Red-haired Boy that cross the generic line between bluegrass and old-time. Compared to old-time, Bluegrass employs a lot more improvisation, includes "blue notes", and vocally at least, a lot of harmony. It is more of a showy, performance oriented style that emphasizes individual players' virtuosity. Curiously, unlike its predecessors, bluegrass has no connection to dancing, but it is unquestionably a direct descendant of the traditional dance music of England, Scotland & Ireland.

Sharon