I think of a couple of releases that seem to me be creatures of the CD era:
The Centennial edition of The Complete Robert Johnson brought out sounds I don't think anyone ever knew were there.
Though I don't know that it's any great shakes sonically, the 1988 studio cast recording of Show Boat was a revelatory document of what was possibly the greatest American musical.
Another monument of the CD is the encyclopedic box set: the Bear Family collections of Uncle Dave Macon, Louis Jordan and Bob Wills, the Bluebird Fats Waller and the Fremeaux Integrale Charles Trenet are particular prizes to me.
This rock vs. pop thing is obviously some sort of snobbery but I can't quite see what it's being snobbish about.