Dark Side of the Moon is the album which dominated the '70s. Released on March 24, 1973, it ushered in an era of album-oriented rock and transformed Pink Floyd from ranking English acid-rock conceptualists to a goliath of the international super-league. It enjoyed unprecedented chart longevity, especially in America, where it was the group's first album to breach the Top 40. It remains a perennial presence, especially in the CD market, and in the four years since David Gilmour and Nick Mason revived Pink Floyd and set off on the Momentary Lapse of Reason tour, Dark Side of the Moon has sold four million copies, bringing the current sales tally to 23 million.

The album was made during the summer of 1972, at a time of rapid technological change. It was recorded on 16-track equipment at Abbey Road, with the new Dolby noise reduction system being adopted halfway through the sessions. A decision was taken not to do a quadrophonic mix, although that ill-fated system was just beginning to appear on the domestic market. EMI went ahead anyway and commissioned a quad-mix from the then-engineer Alan Parsons, which the record company played at a press conference held at the Planetarium to launch the album. The group did not approve and boycotted the event, their place being taken by life-size cardboard cut-outs.

As was the practice in those days, the Floyd maintained a steady gigging schedule throughout the period of the recordings, but Dark Side of the Moon was the first album which the band had both written and toured before going into the studio.
"It was called Eclipse when we first played it live," recalls Gilmour.
"We showcased it to begin with at five nights at the Rainbow, which tightened it up performance-wise, although one or two of the pieces which were a bit more performance-oriented got thrown out and replaced in the studio. On The Run started as some strange on-stage jam, but when we discovered the sequencer capability of the little VCS3 synthesizer we used that instead."
The album bears the legend 'Produced by Pink Floyd'. "In theory we were all producing," says Gilmour, "but in practice it meant that Roger and I would argue considerably about how it should sound." Chris Thomas (who later produced The Pretenders, The Sex Pistols and others) was called in at the mixing stage as a 'neutral party' to try and resolve the internecine wrangling.

Clearly, Dark Side of the Moon has touched a deep chord with succeeding generations of record and CD buyers, a reflection perhaps of the timeless qualities of both its production and its theme. The production, although basic by today's standards, does not sound unduly primitive. Indeed, there are later Floyd albums which now sound more dated.

This was probably due more to luck than judgement. Although the Floyd have always been renowned for their stringent quality control, their music, like any other act's, was frequently locked into the spirit of its time. But not only are tracks like Money, Time, Us and Them and Brain Damage powerful, concise musical statements, they also boast a cohesive thematic content.
While Gilmour provided many suitably majestic instrumental passages Roger Waters' lyrics bore down with stark perception on a universal subject - the simple, often trivial pressures of daily life that can lead to insanity. Still a couple of years shy of his 30th birthday, Waters had already twigged the ultimate misery of it all, and he wrought his bleak verse with bold slashes of the pen. There was no air of a false new dawn or hippy optimism about this record; rather the despairing observation that with each new day "... you're older, Shorter of breath and one day closer to death."
Dark Side of the Moon has been available in CD format bearing EMI's 001 catalogue number since August 1984, and it remains among the top 10 selling CDs of all time. With it striking sound effects of chiming clocks and ringing cash tills, it is the sort of album that has traditionally appealed to the audiophile section of the rock market and has doubtless been a priority purchase for many proud investors in the new CD technology. Such fans may be surprised, if not dismayed, to learn that the early CD version of the album was transferred not from the master tape, but from a standard 15ips Dolby copy, a practice which David Gilmour believes to be fairly widespread.
"We weren't involved initially. They just went ahead and did it. When we found out about it we had to do an investigation to find out where the original master was, and then have it remastered." Dark Side of the Moon was undoubtedly a high water mark in the Pink Floyd odyssey. Gilmour now recalls that "it changed our fortunes everywhere. We became much more visible. We were selling out 12-15,000 seater venues in America, but thereafter we could sell out vast football stadiums and we had to change our way of doing shows. Whereas we used to get a respectful silence from the audience, once Money had been a hit single (it reached number 13 in America) we had thousands of kids partying at the front. Some of the things we had been able to do previously, such as very quiet sequences, simply didn't work any more."

Waters took a jaundiced view of its impact. Speaking in 1987, he declared that "Dark Side of the Moon finished the group off. Once you've cracked it, it's all over." Either way the album remains a work of rare intensity, a powerful evocation of the shadowy corners of the rock psyche. Plainly unsuitable as an accompaniment for the snappy advertising of beer or jeans, it seems entirely appropriate that the one track from Dark Side of the Moon which has found its way into a TV commercial - keyboard player Richard Wright's haunting interlude for piano and voice, The Great Gig in the Sky - was adopted for a surreal Nurofen painkiller advertisement.

Large chunks of the album still feature prominently in the live shows of both Pink Floyd and Roger Waters and it is clearly a body of work that has become part of the collective rock consciousness. The secret of its longevity is anybody's guess, although one clue may be the curiously reductive quality which it has demonstrated over the years. As Gilmour notes wryly, "I thought it was a very complicated album when we first made it, but when you listen to it now it's really very simple."