Last week I went to the Barbican Centre to see the Ian Dury biopic Sex & Drugs & Rock & Roll. Rarely has a film-showing had a more appropriate environment: the Barbican is stunningly early-70s, a symphony in brown and orange inside its concrete Brutalist exoskeleton. By the time the opening credits rolled, my hair had developed a Farrah Fawcett flick and I was fully expecting to be served a prawn cocktail by someone complaining about the three-day-week. Anyway: I enjoyed the film. It’s an accomplished pinch-of-salt portrait of Dury as child, father, husband, bandmate and musician, peacock-strutting his way from a semi-Dickensian institutionalised childhood to an adulthood spent in raucous and truculent self-actualisation. Andy Serkis is immense, as are the quietly cool portrayals of Dury’s long-suffering first wife and his largely unsung girlfriend, jobbing bassist and general muse Denise Roudette.

How punk was Ian Dury? Speaking musically: less so than his ubiquity on punk retrospectives might suggest. His closest association is with the big-band sound of an earlier generation. Into this mix his band stirred sinuous, sinewy funk, jazz and reggae in a brew that anticipates much of 2-Tone and later white-boy ska. The Blockheads’ sound has the confrontational physicality of early rock n roll, too, dextrous and muscular and thuggishly full-on. The opening verse of ‘Sweet Gene Vincent’ is a rare gem of moonlit delicacy in a barrowload of brutalising rhythms, terrace-chant choruses and that glorious, swaggering, leering, brandished clenched fist of a voice.

Dury’s other big influence is music-hall, traceable in his arch delivery, left-field rhymes and the maudlin lost-world sentiment of ‘My Old Man’, and peaking in the posturing of his Essex swell Billericay Dickie. The chancers and romancers who populate his songs are sometimes indistinguishable from his stage persona, but Sex & Drugs & Rock & Roll efficiently unravels the layers of performance inherent in this: Dury’s wideboy geezerisms are adopted, transposed on a background of art-school bohemia which he memorably describes onscreen as ‘[not posh;] we’re arts-and-crafts’.

Despite his musical distance from it, there is an edge to Dury which aligns him squarely with punk and its particular anti-aesthetic. Not only did punk’s appreciation of the vulgar and iconoclastic dovetail with Dury’s own, but he also embodies empowerment through the owning and reclaiming of one’s own social marginalisation, which Lester Bangs identified thus:

… one of the things that makes the punk stance unique is how it seems to assume substance or at least style by the abdication of power.

Punk allows you, if you can’t emerge butterfly-pretty and slide smoothly away from your shell, to fight your way half-out and carry on, dragging the smashed and broken pieces with you as an integral part of yourself. An uncomfortable, uncompromising process made spectacular. Punk’s gifting of defiant and unapologetic visibility to the powerless, and to those socially excluded on economic or aesthetic grounds, swirls in the venom with which Dury injects his music. It found particular expression in his 1981 commercial swansong ‘Spasticus Autisticus’, a reclamatory refusenik anthem which achieves a dignity of its own through refusing to accept it in its patronising, socially-ordained form. The song’s conception and subsequent banning are explained in this clip:

‘Sex and Drugs and Rock n Roll’, with its exhortations to reject the ordinary and take sartorial and aesthetic pride in oneself, is a manifesto that should be nailed up in every schoolroom and recording studio in the land. Dury was one of our last great originals, a genuine outsider resistant to external definition by background or ability, quintessentially punk and unmistakeably English, whose absence highlights the threadbare, barren and character-free state of contemporary music. As a national treasure, he gives every other contender an unsteady run for their money.