is a four-disc box set that presents all of recordings for King Records in chronological order, as well as four sides they recorded for Federal as supporting musicians for . The set contains many of finest and most influential moments, most of which feature the support of bassist and fiddler . As a historical recording, is invaluable, since it documents the greatest recordings from one of the best bluegrass groups in history. However, it is difficult listen -- this is educational listening, and is not intended for entertainment. For musicologists and dedicated fans, it's a necessary purchase, but country and bluegrass fans intending to build a basic bluegrass collection don't need to purchase this set. ~ Thom Owens