40 Years After Dark Side: Never underestimate the power of 'The Dark Side ...'

It has been 40 years since the release of Pink Floyd's 'The Dark Side of the Moon'. John Rentoul remembers when the cloud bursts thundered in his ears

They were dark days. No, really, they were dark. The year before, in February 1972, as the National Union of Mineworkers' strike started to bite, we had power cuts, on a rota, lasting from six to nine hours a day between 7am and midnight. Candles and cold food. That was fun while it lasted. Soon after The Dark Side of the Moon was released, the NUM began a "work-to-rule". For readers to whom this phrase means as much as "enfeoffment" or "saccage and soccage", this was a way of striking without actually going on strike, which gave the Government more time to plan for what would happen when the coal stocks ran out. So in December 1973 Edward Heath, the Prime Minister, announced that, from 1 January 1974, the country would work a three-day week.

I was 14 when The Dark Side of the Moon came out so I don't remember it as an event. I don't remember the rainbow refraction cover having any effect on me; it was distinctive, that was all. A bit like a school physics diagram. Pink Floyd were for older people, because they only did LPs. More sophisticated schoolfriends would refer to it, and the phrase "concept album" was used, interrogated and explained. But I was interested in singles, and on the day that the prism gatefold hit the record shops, I probably had a radio, which I had smuggled into school, pressed to my ear, listening to the astonishing news that Slade's "Cum on Feel the Noize" had gone straight into the chart at No 1.

So, yes, I was not really there at the forefront of psychedelic rock. I wore flared jeans. I had long hair. I had school shoes with platform soles, despite being 6ft 2 in the sixth form. But that was about as far as it went in Wolverhampton in the 1970s. Or, it did go further, but in a different direction. The fashion was for trousers called "parallels", which were flared from the waist down. The cool kids, such as my sister, were into Northern Soul.

But my friends and I, when we moved on from Slade, were drawn to what we thought was serious music: Genesis, Yes, Emerson, Lake & Palmer – and Pink Floyd. (And it was definitely a boy thing: Pink Floyd were the musical equivalent of Monty Python.)

By that time, The Dark Side of the Moon was just there. A monument that seemed to have always existed. I never bought it. Instead, I borrowed a friend's record and taped it. The album didn't quite fill up one side of a 90-minute cassette tape, so there is a bit of "Ripples" by Genesis at the end, and a Tamla Motown Various Artists compilation on the other side.

I listened to it a lot then – although it is strange to realise that this was never on headphones, but on the radio cassette player in my room or on the turntable at friends' houses – but hardly at all now ("Brain Damage" is on my iPhone, however). It wasn't Floyd's best. Silly sound effects and short, poppy tunes. We did enjoy Clare Torry's ad-libbed wailing and the bitter, introspective lyrics though.

The worst of it was "Money", with its cheap jingle and populist sentiment. I hadn't realised quite how dreadful the lyrics were until I revisited them recently. There is a strange echo of today's austerity-era, rich-hating mood in the mockery of the "I'm all right, Jack" attitude of the "Lear jet" class then. I don't think the "I'm all right, Jack" line referred, even partly, to the sectional selfishness of parts of the trade union movement at the time, either. The NUM, for those of you who weren't there, was bought off with inflationary wage rises both in 1972 and after Heath called the election – while the week was still only three days long – in 1974. As my late colleague Alan Watkins used to write, at frequent intervals, Heath called the election on the question, "Who runs the country?" and the voters replied, "Not you, mate."

Harold Wilson and Heath were regarded by Private Eye as interchangeable objects of derision. There was a public mood, though, and, while it was hardly sympathetic to the miners, it was hostile to the better off, and the Labour Party was regarded as better able to do a deal with organised labour – a mood that wasn't broken until James Callaghan's miscalculation in 1978.

When Pink Floyd sang about money being a crime – "Share it fairly/But don't take a slice of my pie" – it seemed suitably derogatory of the powers that were. I never understood the origin of the term "prog rock", but perhaps that was it: 20 years before Tony Blair adopted "progressive" as a non-threatening label for being a bit left-wing, the band had seen its potential. Blair was a fan, of course, and he really had the look: bare feet, flared jeans, open shirt – although his attempt to break into the music business in his year off between school and university was less commercially successful. He would have taken consolation at the time from the message: "Money/So they say/Is the root of all evil today." We know better now, of course. Not least because we know our biblical pedantry a bit better too, and that it was the love of money that Paul said was the root of all evil. However, it wasn't until "Have a Cigar" on Wish You Were Here in 1975 that we realised the paradox of a super-rich mega-group singing songs about the moral corruption of the profit motive.

Nor could we have known that the very commercial success of The Dark Side of the Moon would become part of overcoming the feeling of the time that Britain was an old country, clapped out and past its best. Pink Floyd would be one of the great floating pigs of a great British export business, selling music and the joy of the one nation capable of feeling Schadenfreude about itself.

Apart from an economy that didn't work, there was a lot else going on at the time. The last Moon landing, Apollo 17, was at the end of 1972. It seemed to fit a wider pattern of human technology, and not just of Britain's standing in the world, having advanced and now being in retreat. The Apollo astronauts had seen the far side of the Moon, but they hadn't landed on it. There isn't one side of the Moon that is always dark: there is a side that faces permanently away from the Earth. Yet it is a great metaphor for the unknown, or little known, or the barely understood; for the themes of mental illness and the passage of time about which Roger Waters wrote.

The real significance of The Dark Side of the Moon, though, was as a gateway drug. It led me and my friends backwards in time to explore the back catalogue of Syd Barrett, the original member of the band who left in 1968 and lived as a recluse until his death seven years ago. He was mysterious and magnetic in the way that living recluses, such as JD Salinger, often are; all the more so because the remaining band members so elaborately paid tribute to him. He was acknowledged as an inspiration for The Dark Side ... and "Shine On You Crazy Diamond" on Wish You Were Here was about him (although when he turned up at Abbey Road for its recording the other band members reportedly did not recognise him without his eyebrows). It is Barrett's weird stuff on Relics that everyone remembers: "Arnold Layne", "See Emily Play", "Bike".

The Dark Side ... also led us forward to Wish You Were Here and Animals, the great works of the Pink Floyd oeuvre. Those were not just concept albums but orchestral in ambition, developing themes over the sort of length that made the three- or four-minute single seem a trite thing until it was brought back to life by punk. Actually, the chronology overlaps: punk began in 1976 and Animals was released in January 1977, so some of us flexible cultural magpies were able to enjoy both at the same time.

That year, 1977, was the Queen's Silver Jubilee. It was the year of "God Save the Queen". It was Peak Floyd. It was the year of the Lib-Lab pact between Callaghan and David Steel. And it was closer to the end of the Second World War than it is to today. It might as well have been the dark side of the Moon.

The Dark Side of the Moon was released in the UK on 24 March 1973. In UK album chart for 30 years and US Billboard 200 for 15 years. Most commercially successful Pink Floyd album. Sold 23m copies worldwide. Sixth best-selling (non-compilation) album ever in the UK (overtaken by Adele's 21 last year).