I agree with guest, There were people long before him that brought to the world Rock and Roll.
And Elvis was lucky because in the 50's Jerry Lee Lewis was in trouble because of his marriage to his cousin, Little Richard had decided to give up the music business, Carl Perkins was invovled in a road accindent so that just left Elvis to get in there with the song 'Heartbreak hotel' and the rest is history.
So he just got the break that he was looking for.
They say that if Carl Perkins never had the accident he would of been bigger than Elvis, however it wasn't to be.
So that's that.