Chris Blackwell was always a bit of a rebel. Born in London, raised in Jamaica, he was schooled at Harrow but scorned its uniform - especially the straw boater pupils were obliged to don.

Hard drinker with a soft heart who outshone many of his musical peers

Soulmates don't always feel the need to tell each other their feelings. It would take the singer-songwriter John Martyn the best part of four decades to let Danny Thompson know, "You're my best friend."

For decades he made some of the most beautiful music Scotland has ever produced, yet his life was haunted by demons which tore apart his marriage and drove him to drink. Now the album which documented his divorce in heartbreaking detail is to be celebrated at Celtic Connections. Jonny Jobson reflects on the grace and danger of a true genius.

In 1978 I got a call from a drummer called Timi Donald, who'd been in the Pathfinders in Glasgow. He told me, 'John Martyn is looking for you. I'm playing with him – would you mind coming in? He's doing production work for Grace & Danger.' I was getting £100 a day for production, which at that time was fantastic.