The wilder shores of contemporary visual art are now ephemeral or time-based: performance, installation, general carry-on and hubbub. But once upon a time – say, the 1960s – it was the nature of objects, pared down to essentials, and often made from real materials sourced from the streets, builders’ yards and shops, that startled: the idea made manifest without old-fashioned notions of the hand-made, craft or manual skill.

The making could even be outsourced, and one critic called minimalism “ABC art”, reduced almost literally to building-block art: form or colour representing nothing but itself with nary an emotional gesture in sight. Dan Flavin used neon tubes, Donald Judd made metal boxes, Robert Ryman painted all-white canvases, Ad Reinhardt took to black. It was an ism that nakedly exposed the fact that art, however constructed, is first of all an idea.

Shock-horror outrage as the rest of the media gleefully followedNowhere was the controversy and perplexity that ensued more manifest than in the accidental furore and scandal attached to the Tate’s purchase of Equivalent VIII, 120 firebricks arranged in a two-brick-high rectangle, six bricks across and ten long by the American poet, conceptualist and sometime freight brakeman for the Pennsylvania Railroad, Carl Andre. The artist, no stranger to controversy both artistic and personal – he was accused of murdering his wife in the 1980s and acquitted after a three-year legal process – is now a revered octogenarian, represented in the most prestigious world collections. What cost the Tate under £3,000 in 1972 (equivalent to about £30,000 today) would be worth somewhere in seven figures now.

It was all a media accident. Equivalent VIII had been shown at the Tate Gallery several times, exciting neither interest nor comment. Cue The Sunday Times, in fact its Business section, dispatching early in 1976 a lively journalist Colin Simpson (who, we were told, left post-Murdoch in 1984 to run a gardening business) to sniff out controversy at the national gallery of modern art: the Tate report containing an illustrated annotated list of acquisitions for 1972-1974 provided rich pickings. Public money – thousands of pounds – spent on 120 firebricks! Bricks! Shock-horror outrage as the rest of the media gleefully followed through the succinct exposé (the Daily Mirror cover, pictured below). And a good time was had by all – or was it?

Clare Beaven’s rather hilarious visual essay jumped all over the place, talking to the survivors of the contretemps – journalists, curators, lecturers – and critics; it was laced with contemporary photographs, interspersed by pop groups singing relevant lyrics, and endless newspaper articles about how the Tate had dropped a brick. In between we had vox pop – two middle-aged ladies saying they did not understand the bricks, but they did appreciate them – and continuing amiable fury from retired chef Peter Stowell-Phillips who had festooned them with blue food dye 40 years ago, and was banned from the Tate for life. We also had actors in unconvincing creaky scenarios reconstructing the events of long ago, pretending to be, among others, the then director of the Tate, Norman Reid.

It was a huge fuss, questions in Parliament and all: at a time of financial crisis the waste of public money by an out-of-touch élite purchasing an incomprehensible “work of art” for the nation seemed to fuel the fury. It remains implicitly astonishing that out of that national anger and noisy debate – the Tate besieged – would eventually emerge Tate Modern, the most visited contemporary art museum in the world.

As usual it was left to a couple of artists (and, surprisingly, the eloquent Brian Sewell) to act as the voices of common sense. Cornelia Parker and Damien Hirst eulogised minimalism with clarity, Hirst – he of the pickled shark, sheep and cows – saying how he wished to inject it with emotion, Parker cogently describing her own art’s debt to the movement. Brian Sewell, notorious for loathing so much about the contemporary, said Tate should have bought all eight of Andre’s varied Equivalents, and then everyone would have understood his themes and variations. Andre himself, shown in various guises, from full-bearded to minimally hirsute, had the last word: his art was made to question, and he did not have any answers.