Boston’s Berklee College of Music has long reigned as America’s preeminent conservatory for non-classical musicians. Jazzers and rockers alike have emerged from Berklee, which has always cultivated an image that falls somewhere between the sophistication of Wynton Marsalis and the populist appeal of Sting. Now, the school is branching out to include a genre it has long disdained – bluegrass. “Berklee administrators credit interest in bluegrass to a growing appetite among students for a range of musical styles, spurred by the Internet. It also parallels the growing popularity of the style nationally.” Appointing a new president with a Deep South upbringing didn’t hurt, either.