“Consider that during his lifetime, his biggest-selling recording, “Terraplane Blues,” sold about 5,000 copies. When the “King of the Delta Blues Singers” LP surfaced in 1961 with 16 of his songs, it sold around 20,000 copies. Since its 1990 release, a 2-CD box set of all his known recordings has sold 1.5 million copies. That’s despite detractors who have suggested his reputation is over-inflated.”