Flatt & Scruggs were almost singlehandedly responsible for giving bluegrass music a national profile in the early 1960s — fortuitously, a time when folk music was becoming a youth-culture craze. (Whether bluegrass fit the “folk music” label was always questionable, but it was at least folk-adjacent.) When they played to an enthusiastic audience at Carnegie Hall in 1963, they had already taken their fame to a new level by supplying soundtrack music for The Beverly Hillbillies, and they run through all their favorites here: “Dig a Hole in the Meadow,” “Salty Dog Blues,” “Hot Corn, Cold Corn,” and even a version of “Big Ball in Boston” rendered slyly as “Big Ball in Brooklyn.” This live album is as good as any of their classic studio recordings.