I ask, not because I am one, but because I'm going to be playing some improvised bluegrass with some friends soon ( a guitarist and a violin player).... only problem is
I have no idea how you play a bluegrass bassline 
So, does anyone have general suggestions for how to improvise a bluegrass bassline?
Fer instance, in hard rock it's fast and heavy on the root, with occasional little flourishes.
So, any advice from you Bluegrass players?