The folk revival frequently takes a lot of heat from bluegrass experts. When a younger urban audience and their ethnomusicologist guides began discovering and drawing attention to established bluegrass artists in the '50s, they sometimes proffered a distorted folk purism to the music--and that can rankle hardcore bluegrassers. Yet without the folk revival, bands as seminal as the Country Gentlemen would not exist--in fact, one of the band's earliest singles was a reworking of the best-known folk-revival performance: the Kingston Trio's "Tom Dooley." This four-disc box set collects the most energetic and groundbreaking work of the classic Country Gentleman ensemble--Charlie Waller, John Duffey, Eddie Adcock, and Tom Gray--as well as the equally great, early-'70s lineup of Waller, Bill Emerson, Bill Yates, and Doyle Lawson. No bluegrass band of the '60s and '70s was more influential: they brought songs by Dylan and the Beatles into bluegrass, not as novelties, but with all the soul of the standards these songs would become. But this isn't hippie newgrass either--the playing is stunning, and the harmonies grip like a vise. --Roy Kasten