All the above merely serves to demonstrate the obsession for analysis beloved of the European musical tradition. The (totally wonderful) Bo Diddley undoubtedly learnt by ear - he heard something he liked and used it and added to it. It was part of an aural tradition although I bet he didn't call it that. What you hear when you hear Bo Diddleys music is Soul, the heritage of a thousand years and more. Some people mistakenly think that they can buy into all this if they write it down in a European musical language. but you gotta hear it to feel it. The nuances of this music don't translate into cold symbols. Just dig it. And another thing: Bo didn't feel the need to write a 3 hour Rock Opera, he can say it all in 3 mins.