With Blood Below the Window, Morton reinvents the concept of comedy. "If you only want to listen to rock albums, you're missing a lot," he explains. "There's Asian drum and bass out there as well." His broad-church redefinition stretches the boundaries of comedy to encompass such unexpected territory as death, cancer and life-threatening injury.
In one deeply moving part of his recollections about the painful process of growing up in Cambuslang, near Glasgow, the stage-lights are dimmed as Morton remembers being phoned by his mother with the news that his sister has died. "I never knew anyone could cry that much," he says to an auditorium in which you could hear a pin drop. "It was a torrent." In a poetic afterthought, he recalls: "I thought I could see Death sitting in my living-room, smoking a cigaretteand dropping ash on my carpet."
It may be affecting, but that is not to say Blood Below the Window is devoid of laughs. Like a joyous wake, it rings with frequent relieving peals. Even in the darkest moments, Morton is capable of finding illuminating shafts of humour. He recollects that, after the fall from the first-floor window that forms the centrepiece of the show, he bled so profusely that "the ambulanceman said to me, `You were like a stigmatic showing off at a party'." Later, when he was recovering in hospital, a friend brought him a "nude book" as a gift: "To a man with a broken wrist, that's just mischief or evil."
Morton softens us up for the tear-jerking sequences with laugh-out-loud memories from his first steps into adulthood. When he finally lost his virginity at 18, he discovered to his horror that the male has reached his sexual peak by 16. "All those peak moments flushed down the toilet - what a waste!"
There are moments when Morton takes unnecessary detours. But in daring to use themes more readily associated with tragedy, he is not so much re-writing the rule-book as throwing it away.