The world has grown darker. Not that you would know. Thirty years in – well, 29 since debut single “West End Girls” - and Pet Shop Boys, the eternal duo of Tennant / Lowe being the best British songwriting pair since Lennon / McCartney, are still to sum up in a word – an experience. The nearest thing the world has to a musical Gilbert & George, Pet Shop Boys are a uniquely British proposition, obvious and yet if they didn't exist, unimaginable to most of us, a mixture of euphoric electronic music, restrained, intelligent vocals, and outlandishly baroque staging. London, who saw Pet Shop Boys play to around 500,000 people supporting Take That two summers ago. For the first time, I am in the corporate box, and not that far from the repugnant tout StubHub and PayPal : who have an empty and unused box.

Last album – the sedate “Elysium” is barely cold in the ground, being nine months old – and already the band are touring the next one - “Electric” that comes out in less than a month. Add to that they have completed a musical about Alan Turing and already played parts of that live, Pet Shop Boys, simply put, do not rest easy on laurels : 16 albums, numerous compilations, around 50 singles and a gamut of productions for other artists. With three decades, they instead play to their strengths, an unstoppable arsenal of great, human pop music, designed to tug at the heart, move the soul and the feet, and make you feel and think. Their music has always been designed for the widescreen, the big picture, and on stages as big as the O2, they work best. With Tennant and Lowe as largely static centrepieces around which the rest of the chaotic staging orbits, the show – two musicians, two dancers, and a metric shedton of lasers – is an exercise in flippant, powerful iconography, taking the easily identifiable visual language and adding meaning through context. At times it is downright absurd – Tennant and Lowe in upright beds ( a a visual callback to the 1991 staging), or Chris Lowe wearing a discoball on which huge lights are aimed in “Leaving.” During “Domino Dancing”, they take leave of the stage to allow the two dancers to move and themselves presumably a cup of tea and a new hat. New song “Thursday” is thrown into relief by a brief guest appearance by Example, who acts as a pedestrian anchor to the broad imagination of the the rest of the evening.

On the other hand, at the core of their music – which is a intelligent disco of the type that was never fashionable – is a curiously human heart and soul. The songs run from heartbreakingly sad ; in this context “Rent” is not so much about a kept lover having an affair as a rich persons secret, but a couple trapped forever in financial servitude. At the same time, Tennant and Lowe look like bizarre priests leading a church rave. The staging seems – relatively – sedate with a backdrop, and – to squeals of my companion – POINTY HATS! - with understated touches – the bands shilouettes have become recognisable, iconic, even, and their back catalogue is presented in a near-ceaseless two hour DJ arrangement, as songs fall into other ones, then back into a third : the opening “Axis / One More Chance / Face Like That / Opportunities” is a quarter hour without a pause in sound. Later on

“Love Etc / Rent / I Get Excited” is a similar aural explosion as one song transforms ceaselessly into another. And look at that back catalogue, with 42 top 40 hits, there are bound to be disappointments.

You could imagine churlishly wondering at the absence of “Being Boring”, “Heart”, “Love Comes Quickly”, “Left To My Own Devices”, “So Hard”, “Can You Forgive Her?”, “Paninaro”, “Se A Vida E”, “You Only Tell Me You Love Me When You're Drunk”, “New York City Boy”, “I Don't Know What You Want”, “I'm With Stupid”, “I Get Along”, “Minimal” - and then recall 2009's show, which shares only 5 songs with this tour and was equally well received. This time round, well known songs that have been forgotten - “I'm Not Scared” which they wrote for Patsy Kensit's Eighth Wonder – are greeted with waves of screams, and b-sides such as “Fugitive” and “I Get Excited”, which is mistaken for a hit by someone who has never owned it, sit more than equal to the big hitters. During said song, O2 is bathed in a sea of lasers, which sounds oddly pedestrian, but I've never seen so many lasers in over 1,000 shows over 2 decades. Not even 90's Orbital or 80's Pink Floyd. It is stunningly impressive in turning a sterile 20,000 seater corporate arena rock shed into a estatic nightclub before 10.30pm on a Tuesday night. The whole venue is on its feet and dancing away.

Sure, Pet Shop Boys never eschew playing the big hits, as such, and you will always get a feast for your eyes and ears, as well as a good half dozen songs that are as important and well-known as anything The Beatles or Elvis did.

Closing your show with a song that hasn't even come out yet is brave, confident, and right. The night seems to last forever and yet is over in the blink on an eye. Pet Shop Boys are a band so unusual that if they didn't exist, I'm not sure anyone would be able to invent them.

Axis - One more chance / A face like that - Opportunities (Let's make lots of money) - Memory of the Future - Fugitive - Integral - I wouldn't normally do this kind of thing - Suburbia - I'm Not Scared - Invisible - The last to die - Somewhere - Leaving - Thursday (feat. Example) - Love Etc. - I get excited (you get excited too) - Rent - Miracles - It's a Sin - Domino Dancing - Go West - Always on My Mind - West End Girls - Vocal