about the jam band thingy - 
GPN has played on JamCruise, toured with Gov't Mule, played a number of festivals alongside lots of other jam bands, sat in and played in the middle of Moe's set - 
so they get along well with the jam band culture and crowds;
but no, they're not a jam band. 
not really.
sort of similar to jam bands during some of their jams, but not a jam band.
they also toured with Brett Dennon - but they are a FAR away from being pop music.
how about we avoid labels, and just call them a damn fine band!