Mark Stewart, who has died, was not past his prime. He was not in his 90s, or 80s, or even his 70s. He was only just into his 60s and he had much more to give.

Stewart was not one of those musicians who burned brightly in his youth and then faded from view, only to be remembered after his death. He remained relevant to the end, as committed as ever to his music and his politics – as this song hopefully proves.

He first made a mark in his teens, with his ironically – nay, sarcastically – named band The Pop Group. They were, of course, anything but “pop” as we knew it, railing against the orthodoxy of pop music.

Their abrasive, jerky fusion of funky rhythms, angrily abstract noise and declamatory political sloganeering, allied to the dubwise production techniques of Dennis Bovell, bore the angry DIY ethos of punk, but took it to a new dimension.

Always fiercely political, the B-side of their second single, We Are All Prostitutes – itself a political statement – was the extraordinary Amnesty International Report on British Army Torture of Irish Prisoners in which Stewart recited the contents of the titular document.

Formed in 1977, they broke up in 1980, their aggressive protest music increasingly at odds with the mood of Thatcher’s Britain, and their leader found new collaborators in The New Age Steppers, Tackhead, and his own band, Mark Stewart’s Maffia.

Their influence cannot be overstated: without Stewart there would have been no Birthday Party and therefore no Nick Cave; no Bristol scene – Adrian Sherwood, Massive Attack, Tricky, Portishead – and much more besides.

Three decades after I saw The Pop Group for the first and only time, I witnessed a spectacular solo show in Islington where Stewart and his band’s performance was live-mixed by his old producer, Dennis Bovell, creating a shuddering dub-like sensory experience.

Two years after that, and 35 years after disbanding, The Pop Group reunited in 2015 and I went to see what I think was their first reappearance, an album launch at Rough Trade East.

In typically confrontational fashion Stewart, always a tall man and now a huge hulk of a man in middle age, emerged from the audience of fellow middle-aged men and women brandishing a megaphone.

Elbowing the audience aside like an intruder, this ominous figure frighteningly recited in a dalek-like voice the title of their comeback album Citizen Zombie – a harbinger of a powerfully political new record that showed he had lost none of his edge. A few weeks later, at The Dome, they were as loud, abrasive and uncompromising as ever.

I am devastated for his family, friends and fans to hear of Mark’s sad demise at the age of 62 and I am certain he had much more to give – as this typically uncompromising song from last year demonstrates.

RIP Mark Stewart