Twenty-eight years before O Brother, Where Art Thou?, West Coast country-rockers the Nitty Gritty Dirt Band brought old-school country and bluegrass to the modern-day mainstream by cutting a double album with first-gen country heroes (Roy Acuff, Maybelle Carter) and bluegrass originators (Jimmy Martin, Earl Scruggs). Tackling country classics mostly from the catalogs of the participants, the record bridges generations with its honest, unadorned acoustic feel and a torrent of timeless American tunes.