VERY VERY few whites were covering black R&B or blues or whatever back then for pop audiences--esp. a whitebread and mayonnaise guy like Boone (and yes--there were whites who
did cover black music then but it was in specialized situations for special audiences). THAT was cutting edge--back then. From where we sit now, it's hard to imagine that the telegraph and Morse code were cutting edge at one point, but they were!
And R&R was still evolving at the time...we recognized that Boone and Presley were different, but not as different as we see them now.