A fair amount of effort has gone into explaining why this musical version of Irvine Welsh’s 1993 debut novel is as relevant now as when the film version was released 30 years ago. Still, the fact that for London audiences it takes a while to become attuned to dialogue that sounds like a vomit wretch one moment and spoken word poetry the next, gives this show its authenticity. A shame then that the tour planned after this West End run has been cancelled and will therefore no longer reach Scotland and the audience best suited to the vernacular. “If Edinburgh of all places is stuck at 19 per cent sales you know you’re f***ed,” said resident director and cast member Kieran Brown. Yet as committed as he and his fellow performers are, it cannot be said that the cancellation is a great loss.