The musical journey of Ricky Skaggs has been a long one, from his younger days in Ralph Stanley's Clinch Mountain Boys to chart-topping success in country music during the 1980's and back to the bluegrass world on his own family-run label. That relative autonomy has allowed Skaggs to explore various themes such as gospel music and now a return of sorts to his country material.
The concept here is pretty simple, and it's spelled out in the album title; all of the songs here were hits for Skaggs during his major label country music career, here they're rendered in more traditional bluegrass arrangements by his current ensemble of players. Truthfully, some of the original hit versions were awful close to bluegrass already, from Highway 40 Blues to Heartbroke, so these rearrangements don't add or subtract anything from their predecessors. Uncle Pen was borrowed from the bluegrass world to begin with, so its inclusion is a no-brainer as well.
Purists could argue that even these arrangements aren't completely bluegrass, with piano and steel guitar, not to mention actual drums and percussion, appearing on many tracks, and cynics could point out the royalties to be gained from re-recorded versions of these songs on Skaggs' own imprint instead of the hit major label renditions.
Neither of those viewpoints really matters much since the songs themselves are still classics, no matter what genre they're played in.