Imagine, if you will, aliens, grey ones, with those big eyes, travelling through the universe and finding a capsule in the sky, representing the people from the planet Earth, a peaceful place (or so it looks from space). On the capsule, the aliens find a recording – it is “Johnny B. Goode”, the 1958 ur-narrative of rock music, Horatio Alger as channeled through the experience of Southern working class youth. “He never learned to read or write so well,” sings Chuck Berry, who died on Saturday at 90 years old, “but he could play his guitar just like-a-ringin’ a bell”. A sort of rock folk-tale, young Johnny can’t do much except play guitar.