It’s almost worthy of Spinal Tap – a collection of the musician’s thoughts, jotted down while in transit on sick bags. But his book The Sick Bag Song provides a window on Cave’s honesty as well as his narcissism, and there’s the odd flash of brillianceWhen you’ve personally witnessed Nick Cave nodding out on heroin and slowly lowering his head into a candle flame – his mass of dyed black hair igniting as you rush over with a tea towel to extinguish the blaze – you are likely to do a minor double-take when, years later, you hear that he’s been made an honorary doctor of letters by the University of Brighton, the English seaside town he calls home.Such is the unlikely trajectory of a musician who, for more than three decades, has staggered along the fissure that separates low life from highbrow art.