In the Pet Shop Boys career of curve balls, the first was probably Ennio Morricone co-writing, with Angelo Badalamenti orchestrating, It Couldn’t Happen Here from 1987’s Actually. What were the masters of loitering, moodiness and the one finger keyboard riff doing amongst such majestic classical surroundings? Of course the same could be asked about tonight, but over the past 30 years Pet Shop Boys have ingratiated their perfectly crafted pop music with the classical world with ease. Their gigs have visited Sadlers Wells, Savoy Theatre, The Astoria. Tower of London, and Trafalgar Square, so the Royal Opera house is logical. And it knows it’s not an opera night because it’s sold out.

Their recent album Super may have joyously embraced Italo-Disco, but sadness still resides at the heart of their tunes. However, not tonight. Well, not much. To be honest the tug between dancefloor and pop radio has always created tension in their music. Two men, their lives committed to music. They stand as equals; it’s implicit, one is simpler happier behind a tron mask.

Nothing builds pressure like £60 tickets selling for £800 the night before a gig. Not that it bothers Tennant and Lowe, a song writing partnership that would match that of Lennon McCartney in respect if they didn’t operate with machines as opposed to the authenticity of rock music – as the recent Pop Kids grinned – “Telling everyone we knew/That rock was overrated”.

From the moment two large eggs arrived on stage to join a sparse keyboard and mic stand, we are prepared for a minimal set amongst such regal surroundings. They emerge to the already playing Inner Sanctum but it’s the last indicator of any prerecorded music. It shamelessly moulds Faithless and Kraftwerk to their own ends, before West end girls (once contemporary record, now historical document) and the Pop Kids strut by. As the delightfully unexpected early B-side In the night introduces us to Paris during the German occupation of World War II, two percussion kits and another keyboard arrive, bolstering the band to five, reminiscent of their finest tour (2002’s Release), marking a vast improvement from the sterile Electric shows.

The live percussion and extra keyboards provide immediate impact. The violinist sets up the strings to the pretentious pop of Love is a Bourgeois construct. It’s frenetic, erudite and only latex masks away from Spitting Image parody, as the protagonist gives up the bourgeois life to slob around. It’s one of their harder songs to love, but they’re clearly enamoured with its bedsit flattery. If there’s any flaw it’s that this could have been replaced by Young offender, So hard or twenty other better songs.

The dance/pop pull is unending; no matter how hard they charge the floor, pop wistfulness pulls them to shadows, none more than the lushness of too-rarely played Love comes Quickly. Its freshly minted bell line is so gorgeous that anyone would struggle not to weep. The live percussion and backing vocals perfectly addresses criticisms of the over-programmed Electric tour, while the lasers, smoke and lights create an otherworldly beauty.

Tennant looks trim throughout, admirably appearing his age as an omnipotent projection as he gazes down upon the maelstrom of hypnotic Inside a dream, that creates such a spell over the audience that its ending comes too soon. That is forgiven as Tennant takes to his keyboard for the gentle stabs of what turns out to a surprise airing of the romantic Home & Dry. If this neglected song was surprised at its return then the oft-maligned Winner probably had to cancel dinner plans. However, it attends in the superior happy/sad remix. The gentle ooo-ahs both bring a respite of warmly quiet romance to the room. It’s followed by a a return to the early 90s raves of Vocal, with it’s lonely and strange singer far from abandoned as 303 synth squiggles shamelessly mine those DIY years of dancing in now forgotten fields.

Sodom and the Gomorrah Show makes a surprise appearance in an welcome electronic rework, while It’s a sin takes the roof off, even if Neil struggles to keep up with backing track. Somehow there’s more to conquer, as a cowbell laden remixed Left to my own devices arrives. It might be a nod to New Order’s True Faith video, but even when expecting the unexpected, the stage invasion of asexual jelly baby telly tubbies takes everyone by surprise, as Tennant, and particularly Chris Lowe doing what he likes best, become one of the crowd. That Lowe even succeeds in a crowd of oversized jelly babies says it all. Devices frankly reclaims Go West as the perfect closer. Perhaps, aware of this, Go West than arrives to stake its claim, and its hymnal bonhomie accentuated by the jumping jellybeans is so hard to resist that the Royal Opera house doesn’t.

The stage light racks lowering alla Kanye West at Glastonbury shows they don’t miss a pop trick, leaving only one logical ending. Domino dancing continues the audience’s vocal participation after Love Etc’s ‘You don’t have to be’s’, leaving only one logical encore. Hoodwinked by its barnstorming grinding riff, the majestic Always on my Mind has happy couples crooning sexual doubt at each other, until everyone is grinning.

Pet Shop Boys have never sounded more relevant. That they continue to write songs and so carefully consider their presentation is staggering. This isn’t the ‘me’ of contemporary pop, it resides with their characters: of pop kids in love with the possibilities of London, of the pseudo-intellectual not wanting to compete, the sad old dictator who’s ‘too weak to be strong’, the young boy faced with difficult choices at a difficult age. the East End boys and West End girls and the glorious hope of Se A Vida A finding companion in the abandonment of the New York City Boy out in the ticker tape. This is the most modern show out there. Pet Shop Boys have somehow done it again.

My novel, the Life Assistance Agency was published on 22nd September and is available to buy here –   It’ll be the best £8.99 you’ve spent since you bought a square foot of carpet.