Like country, jazz and blues, folk is one of those peculiar sub-genres of music that very rarely gets an opportunity to shine in its own right, but consistently reveals itself through its enduring influence on the mainstream.

In the case of folk, one need look no further than the current No.2 on the UK singles chart (Ed Sheeran’s Galway Girl), a faux Celtic jig, replete with fiddle and a-chatter with reminiscences of Galway.

Indeed, Sheeran himself, in many ways, fits ...