Bruce started out playing in jazz and skiffle bands in his native Glasgow before gravitating, along with like-minded musicians from Belfast, Newcastle and Manchester, towards the blues and R&B scene in London where he played with Blues Incorporated, the band led by Alexis Korner (a mentor to many of them), John Mayall's Bluesbreakers and Manfred Mann. In 1966, he formed the blues-rock trio Cream with ex-Bluesbreakers guitarist Eric Clapton and ex-Blues Incorporated drummer Ginger Baker (I've got a diagram somewhere showing how musicians swapped bands in the British blues and R&B boom).
I'm happy to say that there are still a few people left from that generation of British blues musicians, including John Mayall - who I'll be seeing when he plays Manchester tomorrow night - and Paul Jones, with whom Bruce collaborated in Manfred Mann. Others though, like so many musicians, succumbed at an early age to drug and/or alcohol problems.
Here's Bruce on bass in Cream playing probably his most famous riff .