Before starting with writing another contribution to the question: "Who was the first to turn from Rhythm and Blues to Rock'nRoll?", I have to bring forth a disclaimer: "Rock'nRoll" is a constructed category like "Shamanism" or "Religion" - all these concepts have their roots in the human - some say, in the European - mind's need to organise the perception of the outside world into neatly adjusted categories. Be that as it may, Ellas Otha Bates, a.k.a. Ellas McDaniel, a.k.a. Bo Diddley is my choice for the one who played the main role in inventing Rock'nRoll, for the simple fact that he is credited with the introduction of the so-called "Bo Diddley Beat" to Northern American Popular Music. Later on, this beat has been used in many recordings in the history of Rock Music. Here is the 1955 rendering of "Bo Diddley", allegedly tne first use of that rhythmic pattern in NAPM:
This rhythm is played on the toms or on the snare drum (with the snares turned off) and the toms by the drummer and normally transcribed like that:
On drummers' blogs you will find a lot of discussions about the sticking - whether you play it hand to hand or all the accents with one hand or use some triplet pattern attached to straight eights to achieve a kind of swing feel and the like. Be that as it may, the "Bo Diddley Beat" is actually based upon the 3-2 son clave, and sometimes it is simply written down in the same way as the 3-2 son clave (and called a five-accent-pattern, accordingly):
This clave is the backbone of Afro-Cuban music, it is used in Brazilian music and in Haitian Vodun drumming. It stems from West Africa. This closes the discussion of who might have invented IT. Africa locuta, causa finita. I go on with a rendering of "Hey Bo Diddley" introduced by one of the inventors of Rock'nRoll in the 60ies and another version of "Bo Diddley" from Bo's later years (introduced by a man with no less importance for NAPM) - his stage presence explains why he has (more or less) died from the consequences of a stroke he got after performing. And here he uses his trademark self-built square-shaped electric guitar (solely for building that instrument he is to be called the godfather of Rock'nRoll) - Hey Bo Diddley!.
And finally another famous use of the "Bo Diddley Beat" from the early days of Rock'nRoll, Johnny Otis' "Willie and the Hand Jive" (already featured on this blog before):