If it hadn't been for the Pet Shop Boys I don't know what I'd be doing now. Everything that school doesn't teach you - about taking good pop culture as seriously as any good art, about the importance of living life on your own terms and pursuing your passion - they did, with the added bonus of songs so good, both musically and lyrically, that they remain imprinted on my mind 20 years after I first heard them.
Without their records, I doubt I'd have worked out that it was OK to be a swot and a misfit as long as you appreciated the value of a great, soaring disco hit such as "Always On My Mind", their Christmas number-one single of 1987, for lifting your spirits when you felt alone in the world. Neil Tennant's lyrics spoke movingly of the desire to escape your background into a world where you were accepted simply for being you, and where difference was something that was celebrated rather than stamped out.
The Pet Shop Boys' presence in the mid-1980s charts briefly overlapped with that of the Smiths, but while the Mancunians were relentlessly glum in outlook - and therefore most attractive to grey-cardiganed college students - the Pet Shop Boys were more like an improving, if desperately unlikely, boy-band, regularly featuring on the cover of the teen pop magazines Smash Hits and Jackie well into their thirties. In interviews with Smash Hits, they would refer casually to the existentialists and send me rushing to the nearest dictionary, which was more than could be said for my homework.
The secret of their enduring success lies as much in their presentation as in their songs, which is why they are the subjects of an imminent exhibition of photographs at the National Portrait Gallery in London. A new book, Pet Shop Boys: catalogue, expands on the NPG show and gathers two decades' worth of record-sleeve designs and photo sessions in a typically sumptuous silver-lined hardback. In 1,100 images, it documents a parallel universe in which the duo exercise minute control over every aspect of life on their version of earth, making it glamorous, hedonistic, thoughtful and aesthetically pleasing - and never, ever dull.
The way they present themselves has changed, mostly subtly, but on occasion drastically, for each of the 40-odd singles they have released since "West End Girls" drifted to number one in 1986. What sticks in the mind, however, is the memory of Tennant, his hair already thinning, standing solemnly in a long black coat in front of the microphone while Chris Lowe made a sullen stab at keyboard-playing behind him on Top of the Pops. By doing what no other pop stars dared to do on stage - as little as possible - they established an image that enabled them to see off entire lesser musical movements without ever having to change in ways they did not want.
For 20 years we have watched them take this passive/aggressive stance while wearing things you can't imagine anyone else being able to wear without falling over laughing. They have posed in American tennis gear (for their first single in 1984); as Hergé's characters the Thompson twins (for their 1991 tour); in giant conical hats and orange jumpsuits (for the Very album in 1993); and, most recently, in Union Jack bowler hats to publicise this year's album, Fundamental.
Tennant, who founded the band with the architecture graduate Lowe while working as a music journalist in the early 1980s, was an obsessive David Bowie fan who both adored pop stars and understood a simple fact: the whole point of such artists is that they are not quite of this world. In the self-created world of the Pet Shop Boys, there was nothing wrong with writing a song about Che Guevara and Claude Debussy (their 1988 hit "Left To My Own Devices") and expecting it to get to number one, or redefining "popular entertainment" to include a tour of the nation's arenas with a stage show conceived by David Alden and David Fielding of English National Opera.
They are a rare example of how a band has brained up without dampening its appeal. They have collaborated with the photographer and video artist Wolfgang Tillmans and the architect Zaha Hadid, among countless creative figures whose names, let alone work, might otherwise never have reached a pop-star-sized audience. To those who persist in believing that high culture is for the sliver of "deserving" brains at the top and pop culture is for the masses, the Pet Shop Boys' retort would be that nothing is too good for the workers.
They encourage us to believe that most pop music is dreadful not because the intended audience is stupid (it's not), but because the people who make it lack the courage of their convictions and hold the genre in contempt. The pair's aim, which they have achieved through sheer tenacity and self-belief, is to prove that pop music, like any other endeavour, has most integrity when it's done well. That is why their documentary DVD, A Life in Pop (also released this month), is so titled: they have made the spirited defence of good pop their life's work.
Roger Scruton, as the historian Philip Hoare notes in a foreword to the book, wrote in his wrong-headed Intelligent Person's Guide to Modern Culture that he doubted the Pet Shop Boys had ever made more than "a minimal contribution" to their own records. Not only could they prove that they wrote, co-produced, played and promoted just about every record and associated artefact they had ever made, they sued him - and won. Did Scruton think that pop stars could be libelled with impunity because they're all daft? He couldn't have picked a worse fight.
If it's their world, reason Lowe and Tennant, anything goes, just as it does in Billy Liar's fictional empire, Ambrosia. In one memorable instance - alas, it is not documented in Catalogue - Lowe was photographed for a Smash Hits picture spread wearing a skintight cycling leotard, swimming goggles and a fisherman's mac. Girls (or at least the half-dozen girls with whom I was in frenzied Pet Shop Boys-related written communication at the time) went crazy for it, which just shows you how all manner of transgressions can become acceptable when given a bit of popular coverage. Strangely, Lowe was never called a pervert for his dress sense. It would be hard to see Justin Timberlake getting away with it.
In an interview at the end of Catalogue, their biographer Chris Heath asks Lowe and Tennant whether they are "still trying to create a world" by ensuring that every one of their perfectly executed records is matched with an equally polished sleeve, video and promotional photograph. Flicking back through the book, I alight on pages filled with pictures of Tennant, whose seat on the board of national treasures is being kept warm for him by Alan Bennett and Jarvis Cocker on an alternating basis, until he decides that accepting it would be a sufficiently "Pet Shop Boys" thing to do. He is wearing false eyebrows and an orange wig with an imperious, dare-me expression. "When I was a kid," he tells Heath, "I made a pact with myself that I wasn't going to have a dull suburban life. That was really, really important to me. Well, I have avoided it, thus far."
He may not know it, but I suspect he's helped countless others to avoid it, too. Of course, there is nothing written in stone saying that suburban lives are by nature dull. But I know what he means. If you have a fervid imagination, you want your pop stars to bring your daydreams to life with all their resources. By excelling at this, the Pet Shop Boys have shown that a life in pop is at least as good as any other.
"Pet Shop Boys" opens at the National Portrait Gallery, London WC2, on 30 October. For more information log on to: www.npg.org.uk
"Pet Shop Boys: catalogue", edited by Philip Hoare and Chris Heath, is published by Thames & Hudson (£29.95)
Research by Olivia Shean
1981 The Smash Hits journalist Neil Tennant and Chris Lowe, a one-time architecture student, meet in a shop on the King's Road, London.
1984 The band's debut single, "West End Girls", is released to minor success in America, but flops elsewhere.
1986 The duo having signed to EMI, a new version of "West End Girls" becomes an international chart-topper, selling an estimated 1.5 million copies worldwide.
1987 The Pet Shop Boys receive BPI and Ivor Novello Awards for "West End Girls". Their remake of Elvis Presley's "Always On My Mind" is the Christmas number one.
1988 "Heart" marks their fourth UK number one, with Ian McKellen starring as a wife-stealing vampire in the accompanying video.
2001 A musical by Tennant and Lowe, Closer to Heaven, opens at the Arts Theatre in London. It gets mixed reviews and closes earlier than expected following poor ticket sales.
2004 The duo compose a soundtrack for Sergei Eisenstein's classic 1925 silent film Battleship Potemkin, and perform it at a free concert in Trafalgar Square with the Dresdner Sinfoniker.
2005 The Pet Shop Boys headline the Moscow Live 8 concert in Red Square.
2006 The single "I'm With Stupid", whose promo video features Matt Lucas and David Walliams, satirises the relationship between George Bush and Tony Blair. The Pet Shop Boys remix of Madonna's "Sorry" reaches the top spot in the UK. Fundamental, their ninth and most recent studio album, is released in May.