Free were in the vanguard of the blues-rock revolution that chnged the face of British music in the late 1960s.

Free are high on the list of bands I wish I had seen live, but I was born too late to catch them in concert – the band formed as teenagers in 1969 lasted barely three years.

Andy Fraser, the bass guitarist, left in 1972; they broke up a year later and Paul Kosssoff, arguably the greatest guitarist of his generation, died three years after that at the age of 25.

Watching and listening to live clips today, I’m struck by just how bluesy they are; I had probably never heard actual blues music when I first heard them at the age of 12. 

Paul Rodgers’ full-blooded vocals, accompanied by primal grunts and groans, and Kossoff’s facial contortions as he bends those strings, externalising all the pain of his addiction, are front and centre.

But listening now, it’s Fraser’s bass playing that stands out the most; it’s remarkable to think he was just 16 here – and already a veteran of John Mayall’s Bluesbreakers by then.

He doesn’t just provide the backbone of the songs, in perfect partnership with drummer Simon Kirke, but plays inventive lead melodies in counterpoint to Kossoff.

Never more so than on this live performance, where he follows the guitarist’s incendiary solo with one of his own.

I doubt I would have appreciated his huge contribution back then. I do now.