2010 three CD set that has been compiled to represent the three most commercially successful groups of the post-war explosion of traditional bluegrass from its "labor pains" in 1945 through its widespread acceptance in the late 1950s shortly before the revolution in progressive Bluegrass. As with the beginnings of all new music, early Bluegrass was fraught with animosity between rivals and former colleagues, incestuous relationships between the personnel of the first bands and professional jealousy, but these three CDs contain arguably the greatest examples of this newly-minted music from its greatest purveyors.