"I think that as the folk music "movement" moved away from the "Great Folk Scare" of the 60's and more into tradition-based modes such as bluegrass, old-time and Irish music,"

Bluegrass, "traditional"??? Hardly. It's a modern, commercial, consciously designed music, whose originator and general (modern) time of origin are well known. The name refers to the band, The Bluegrass Boys, where it all started. The name of the band does NOT refer to the music, but the other way around.

Dave Oesterreich