Amazon.comRounder compiled this superb 50-song set to serve as an introduction to bluegrass in general and to their own catalog in particular. Obvious marketing motives aside, the collection has few weaknesses and offers a broad look at the ever-morphing genre. Perhaps more than any other label, Rounder gave exposure to the renegade progressive and "newgrass" musicians who worshipped the style despite the fact that they weren't from the mountains. Folks like David Grisman, Bill Keith, Tony Trischka, and Bela Fleck push the music in new directions while others such as Del McCoury, Don Stover, James King, Jim & Jesse, and Vern Williams represent more-traditional concerns. Still others--Tony Rice, David Grier, J.D. Crowe, Nashville Bluegrass Band among them--adeptly fuse elements of tradition and innovation. This collection also highlights the important contributions of female artists including Hazel and Alice, Laurie Lewis, Claire Lynch, and Alison Krauss. --Marc Greilsamer