The Beatles were not the beginning of Liverpool music but they are an almost inescapable starting point. In fame and influence the group stands at the zenith of our narrative arc: in them we can trace everything that went before, and their imprint is seen on everything after.

Through the Beatles' writing we see a city's whole history distilled, its musical traditions alchemized. Never before, and seldom since, was an act so closely identified with its place of origin. In 1963 the Beatles' accent and presumed attitudes fed a universal conception of Liverpool as young, fresh, cheeky and optimistic. If the impression proved shortlived, there was at least an authentic connection between the group and its home city. This is not to stuff the butterfly back into its chrysalis – the Beatles were undeniably original, and developed in ways that nobody could have predicted. But our initial proviso remains: the Beatles were inheritors of Liverpool's musical tradition rather than its inventors.

John Lennon and Paul McCartney became songwriters because, in the feverish activity of Liverpool's beat scene, there was a shortage of American rock and soul songs for each group to cover. Few of their rivals aspired to be writers: in that time of Tin Pan Alley it was considered a specialist craft. (Ironically, the first Liverpool rock star Billy Fury, the Beatles' immediate predecessor, was a rare exception: he penned several songs, some under a self-effacing nom-de-plume, Wilbur Wilberforce.