Musicologists are convinced blues icon Robert Johnson’s recordings as released are 20% faster than he performed in two solo sessions in 1936 and 1937. It’s unclear whether they were sped up intentionally (to push their excitement, which seems hardly necessary) or accidentally at some point in the chain between microphone and pressing plant. What is obvious is that since only 11 of the 41 existent Johnson takes were issued by Vocalion on 78 rpm discs during his lifetime (and one posthumously), his complete documented repertoire of 29 tunes issued on two Columbia Records lps, King of the Delta Blues Singers (1961) and King of the Delta Blues Singers, Vol. 2 (1970) and finally 41 tracks, alternates and all, released on a best-selling 2-CD boxed set, Robert Johnson The Complete Recordings by Columbia in 1990, we have probably never heard what the blues’ most influential singer-guitarist actually sounded like.