This isn't the definitive biography of Martyn, but it will have to do until one comes along.
I picked it up knowing that Martyn was an exceptionally gifted guitarist and songwriter, an alcoholic who consumed industrial quantities of booze and drugs, and (often as a result) an aggressive and perhaps unpleasant person to be around. And when I'd finished the book, I still didn't know much more than that.
This isn't necessarily Munro's fault; he's pretty open about saying who would (and wouldn't) be interviewed for the biography. But sometimes the lack of background personal detail is surprising. For instance, Martyn's five-year relationship with (Julianne) Daisy Flowers is dealt with in just two paragraphs (in which Flowers describes Martyn as 'unbearable', 'vicious' and 'violent'). Similarly, his marriage to Annie Furlong, which lasted nearly seven years, is again scarcely mentioned, except for a quote from Martyn in which she is summed up as 'permanently drunk' (Furlong's family maintain she only became an alcoholic after suffering years of abuse from Martyn).
And so we end up with a lopsided view of the man, in which his drunken antics on tour and on stage are the stuff of frequent and lengthy anecdotes, but the years of abuse which he meted out to his wives and partners is skated over or (sometimes) ignored altogether.
I would have liked to know more about his relationship with his children, too. Son Spenser is mentioned on page 96 (as a baby) and then again not until page 164, when he's 16 and playing with his father on stage! Presumably in the intervening years the two had some contact, and maybe Martyn was an adoring and supportive (absent) parent, but we're not told one way or the other.
Stylistically, the book is no great shakes. It's worthy but pedestrian, and rarely inspired. In fact, much of the book is taken up with long quotes from articles or interviewees, with Munro just providing the bridges. The albums are all represented, with an obligatory mention of outstanding tracks, the recording process, and some excerpts from critical reviews. All very useful if you want to make sure you're not missing anything essential from your collection, but it's only rarely that Munro conveys any unbridled enthusiam.