Neil Tennant - a jovial if slightly shy presence, with more of a Geordie accent than might be expected - takes up the story: "When we toured South America for the first time at the end of 1994, we heard a lot of samba stuff and thought it would be interesting to use it as a kind of rhythmic base."
Depending on which way you look at it, this was either a very Paul Simon thing to do or the perfect starting point for a heartfelt tribute to disco's Latin roots. "When Chris and I used to make demos a long time ago," Tennant explains, "We used to have this di-di-doo-di-di-di-di-doo-doo noise. We just thought of it as a New York disco thing, but someone in the studio said, `I like those Latin bits'." In the early Eighties, when the Pet Shop Boys first started working together, they had very definite ideas about what they wanted to do. "We thought, `no one else is doing gay disco, no one else is doing New York hip-hop with white vocals' ... when `Blue Monday' by New Order came out, I more or less burst into tears."
Before their remixed "West End Girls" finally went to No 1 in January 1986, the Pet Shop Boys thought they'd missed the boat. Fortunately the good ship Anglo-Electro-Disco proved to be a roomy vessel. "I remember being interviewed by this guy in America," Tennant bristles, "who said, `Groups like you and New Order make this great music and then just whine over the top' - he presented it as if it was a choice, as opposed to singing like Jocelyn Brown or Otis Redding. I said, `Unfortunately, that is all we can do'." That's the history of pop music though, isn't it? From Jerry Lee Lewis to the Rolling Stones, something is added by white people getting black music wrong.
"That's definitely true of us. What you can't do is always what shapes your sound and defines your style. Though having said that," Tennant twinkles defiantly, "we are getting better." Does he get fed up with understatement? "Not at all. I realise a lot of people don't like my voice, but to me it expresses quite a lot of emotion - there's a yearning quality to it which I really like."
One of the greatest and most widely prevalent misunderstandings about the Pet Shop Boys is that they are somehow not emotionally engaged in what they do. Listening to Tennant's voice fairly quiver with passion as he recalls his excitement when Sonia nearly won the Eurovision song contest, it's hard to know how this misapprehension could have come about. It is, Tennant admits, partly the Pet Shop Boys' own fault: "We've always tried to make it look effortless, as if our pop career was something we dashed off in between doing something else much more important."
So it hasn't been as easy as all that then? "It always feels like you're on a bit of a knife-edge, actually. That's why it irritates me when Russian journalists tell me - as they do - `You worked at a magazine and learnt how to make perfect pop records, and then you did it' ... I want to say, `Go on then, you try'." Fortunately, it is not necessary to have seen all the appalling and justly unsung bands in which successful music journalists have been involved to agree with Tennant's contention that his having once worked at Smash Hits is "kind of irrelevant" to his subsequent pop life.
It's not as if the Pet Shop Boys' story has been one long cunning plan, a career devoid of mistakes - anyone who has seen their disastrous feature film, It Couldn't Happen Here, will tell you that. The widespread over- emphasis on Tennant's media-hound antecedents is actually the product of critical frustration. From "Che Guevara and Debussy to a disco beat" ("Left to My Own Devices") to "You've both made such a little go a very long way" ("Yesterday When I Was Mad"), Tennant has written his own reviews in a sufficiently witty and trenchant manner as to render further interpretation superfluous.
In parallel with their own meticulous and impulsive career, the Pet Shop Boys have sustained a stylish critical commentary on the rest of pop music. "We always have an opinion on where it's at," Tennant insists, amid learned discourses on whether the new Boyzone single is as good as the last one (it isn't) and the chances of Kylie making it as a "mature artist" (not good). "I think a lot of pop stars do - we are only unusual in expressing it publicly."
The Pet Shop Boys' distinctive vision of "where it's at" has shaped a remarkable and generous history of collaborations. From remixing Blur's "Girls and Boys" so it sounded like a proper disco record, to adding a chorus and a backbeat to David Bowie's hilarious Babylon Zoo tribute "Hello Spaceboy", to valiantly striving to liven up the new Tina Turner album, there seems to be no limit to their promiscuity. "The thing that links most of the people we've worked with," Tennant insists, "is that you think, `We're doing a record with so and so', and then you think, `Wow'." There seems to be an element of righting wrongs as well: Liza Minnelli has never had a hit single, so why not write her one?
"The only time that was really the case was with Dusty Springfield, who didn't even have a record deal before `What Have I Done to Deserve This?' ... But time passes so quickly ..." Tennant pauses. "That's nearly 10 years ago now. It's already receded into the past. On her new compilation you get Dusty in the Sixties, the Britpopper; then the Seventies, the disaster years; then the Pet Shop Boys Eighties; and finally Dusty in the Nineties - she's already left us behind," he adds wistfully, "I quite like that."
"I'm Not Scared" - the Pet Shop Boys' song for Patsy Kensit - was on TOTP2 recently and it sounded fantastic. Needless to say, Tennant saw it too. "I thought, `Fucking hell! [He winces at the thought of how that cheery profanity will look in print] There's a bit in French: how embarrassing'." He smiles fondly. "Patsy has a great quality, which is that she'll do anything. We felt she deserved to be a star but wasn't making the right kind of records." Why did they make her sing, "Take these dogs away from me" - was that a kind of test? Tennant laughs. "She's being threatened by her man and she's not gonna take it," he explains. "The dogs are his gangstery pals ... also it's a line from Betjeman."
There are a few of those in the Tennant/Lowe songbook - the touching funeral-lament "Your Funny Uncle" springs to mind. Some people like to see Tennant as an inheritor of the literary tradition of Oscar Wilde and Joe Orton - how does the man himself feel? "I don't really see myself that way. The only specific literary influence I've had in terms of songwriting is The Waste Land by TS Eliot. That would be a great rap record: all the different voices in it - going into German, the conversation on top of the bus - that's what I was trying to do with `West End Girls' really."
When Neil Tennant met Chris Lowe in (appropriate venue) a King's Road electronics shop 15 years ago this summer, he'd been writing songs for years. "I'd already had my career - which of course wasn't really a career - in my bedroom as a singer/ songwriter. Chris absolutely loathes the entire concept of that kind of music: his hatred and detestation for it is quite beyond belief." Heeding Lowe's imprecations to make his words "more sexy, more current", Tennant "completely changed" the way he wrote.
An act of will wasn't enough though: the technology had to be there too. "When the Fairlight 2 was invented," Tennant says nostalgically, "the Pet Shop Boys started to exist. Every single sound on our first record apart from my voice was played on an emulator: bass sample, string quartet sample, the `aah aah ooh' from James Brown, the drums from David Bowie's `Let's Dance'." Chris Lowe insists the drums were from Michael Jackson's "Billie Jean": make of that what you will. Perversely, it is the Pet Shop Boys' very freedom from conventional notions of musical authenticity that has enabled them to make such profoundly modern and authentic music.
It was no accident that "Opportunities (Let's Make Lots of Money)" could have been a punk song. The Pet Shop Boys were the first pop stars to sound (and look) as if they had no roots in any music before the Sex Pistols. "It was meant to be an attitude thing," Tennant insists, " `Let's just state the obvious over a gorgeous over-produced backing track'." As a description of their career, "stating the obvious over a gorgeous over- produced backing track" just about puts it in a nutshell. On this year's Song For Europe programme, Tennant said "a pop song should always try and say something that hasn't been said before". Isn't that rather a lofty ambition? "It's the most difficult thing you can do, but you've got to try, because when someone manages it - and I think we have a few times - it's the best thing ever."
The second tune on the new Before EP is the first Pet Shop Boys song to quote from Oasis. "The chord change comes from `Some Might Say'," Tennant admits brazenly. "That guitar break where they go, `uh uh uh uh'." The Gallagher brothers' delirious male-bonding festival has clearly opened up a rich vein of inspiration: "The Truck Driver and His Mate" is also the first pop song to address the homo-erotic subtext of the old Yorkie ads.
Last year, Neil Tennant gave an interview to the gay magazine Attitude in which for the first time he was explicit about his sexuality. The article's assertion that the Pet Shop Boys' brilliant last record, Very, was "an album about what it means to be gay in the 1990s" (yes, but that was not all it was) was the perfect illustration of why he hadn't done this before. "It's great to be ambivalent in pop music," Tennant insists, somewhat regretfully. "It's much more fun to have everyone reading things into what you do, because then you can do something blatantly obvious and pretend you haven't. Now it's all sort of normal and healthy, it's a bit boring really. It makes me feel like telling everybody I'm straight. I told Ian McKellen that I was sick of being gay and I was going to get a girlfriend and he said, `Don't tell anybody'."
Tennant pauses, "Actually part of me - I can say this now I've `come out' - thinks it's all a bit of a cliche anyway: we've invented this thing called homosexuality and now everybody is conditioned into having a way of life which is either gay or straight. I mean 50 years ago I'd have been married with three children and having affairs with men on the side and frankly, I'd probably be happier."
But isn't the great thing about the Pet Shop Boys the way they've left that kind of thing behind? The gay gene in pop music has so often been seen as something to be hidden away, whereas the Pet Shop Boys have managed to appeal simultaneously to a gay and a heterosexual audience without being dishonest. "What we do is more about a gay ideal than the way things actually are. That ties in with a certain kind of romanticism that we both have: it's a mythic thing really, rather than being totally truthful." But it is truthful in that pop's gay iconography is at least partly one of deceit, and the Pet Shop Boys have never been deceitful.
"Chris and I always complain that we're not really icons," Tennant says ruefully. "These are our two complaints: 1) We're not icons; 2) We've never written a rock classic." But hasn't the whole idea of being an icon ceased to mean anything as a result of Athena and the Eighties? "Jarvis is an icon though, isn't he? When you see the Chris Evans programme and that horrible cut-out's standing behind him, you think, [jealously] `God, he's such an icon'. He represents - and this is what you do when you represent - either what he is or what people want him to be."
But surely that's exactly what the Pet Shop Boys do too? Whether we - or they - know it or not, we all have cause to be grateful to Neil Tennant and Chris Lowe: for breaking their own rules, for demonstrating that culture and commerce are not in fact opposing forces, and for constantly changing, even though whatever they do will always be described as "typically Pet Shop Boys". In these insular and triumphalist times, British pop music needs their international sophistication more than ever.
CHRIS LOWE opted to prove just how ill-founded his reputation for elusiveness is by not turning up for this interview. When the mighty Parlophone arm- twisting mechanism compels him to ring up three days later, it transpires that he had decided to go back to his hometown of Blackpool for the weekend.
Does he like it there?
I really look forward to going back to Blackpool. It can't be denied that when you arrive there, everyone is having a laugh: it's just a lot of legless people enjoying themselves, there's no pretence - no one's standing around being aloof.
But that's what everyone thinks you like doing!
I don't mind that - there being a difference. In fact it's better that way. I prefer people saying, "You're not a bit like we thought - you're quite nice really" to "I used to like you, till I met you".
Given your legendary hatred of all forms of rock music, your fondness for Oasis has caused a lot of raised eyebrows. Is it true that they learnt everything they know about stagecraft from you?
We met Liam at Earl's Court and he was really nice. He said, "You're like me: we both do that not-doing-anything thing."
How do you feel about being left out of this interview - do you trust Neil to give a fair account of you?
I'm quite happy about it. I think Neil quite likes giving interviews and he normally does a pretty good job - he's got a much better memory than me.
Are you like money and youth - most poignantly experienced as an absence?
[Unconvincingly] I'm sorry there's a funny crackle on this line, could you repeat the question?
Do you prefer to be a shadowy figure, lurking enigmatically in the background?
Yes, I do actually.
! `Before' (Parlophone, EP) is out tomorrow. The new Pet Shop Boys album follows in September.