You Ain't Talkin' to Me: Charlie Poole and the Roots of Country Music
I downloaded this some time ago. The three CD box-set includes the sides which Charlie Poole and the North Carolina Ramblers made for Columbia between 1925 and 1931. In addition to Poole's original recordings, the package features performances by other early roots music players and singers. I recommend getting this if you are into old time/country/string band stuff.