It’s a pub argument as old as pubs, or arguments: what is the greatest Beatles album? The hip view is to plump for Revolver, or perhaps even The White Album. I’d make a personal argument for side two of Abbey Road, but for many it’s Sgt Pepper’s, certainly the most famous one. Last year saw it’s fiftieth anniversary, marked by a Giles Martin remix, to counteract the less-than-great stereo mix of old. It sounded fantastic, of course, and the various discs of outtakes were the stuff of Beatle dreams, but I’d still go for the bang of the mono mix from the 2014 vinyl box.

At the time of the anniversary, yours truly appeared on a radio show to talk it up, and my main point was that here was an album that had to be taken in its entirety, it was as a thing itself more famous than any of the tracks on it. Yes, the new bells and whistles editions add the concurrent double a-sided single release, ‘Strawberry Fields Forever/Penny Lane’, but shoehorning this onto the original running order is the kind of heresy that, quite rightly, should see people put to death by fire.

See what I mean? I could argue the minutiae of this for the rest of the year. It’s a work of genius that will be celebrated and discussed as long as humanity endures. And here we are again, for A Celebration of Sgt Pepper: The UCD Symphony Orchestra and the world’s premier Beatle group The Bootleg Beatles come together for a special concert to mark the fiftieth anniversary of arguably the most influential album of all time, Sgt. Pepper’s Lonely Hearts Club Band. Pepper originally came out in May ’67, so it’s closer to fifty-one years ago, but no matter, the smiling throng, some in improvised Pepper regalia, pouring into the Bord Gais Theatre, are not about to argue menology.

The stage set – Vox amps, cut-outs from the Pepper cover, and the familiar “flower” arrangement – is exciting, but even more thrilling is the sight of the UCD Orchestra seated across the boards. A voice comes over the tannoy, warning us we’re “not allowed to smoke…anything”, before our host for the evening, RTE’s Shay Byrne, complete with libretto, regales us with a potted history of Pepper and 1967. Byrne comes across as a pleasant sort of chap, although his presence seems just a tad superfluous, but he keeps the ball rolling, which I suppose is the general idea. Before the main event, the orchestra, led by conductor Dr Ciaran Crilly, run through a couple of Beatles medleys, which are pleasing enough and have the crowd singing along to the likes of ‘Magical Mystery Tour’ and ‘All My Loving’ but we’re not here for the amuse-bouche.

The Bootleg Beatles, who’ve been at this game in various guises since 1980, taking the stage in the full Pepper rig out is, to borrow a phrase, guaranteed to raise a smile. You ignore the rational part of your brain and beam with delight at the site of the fab four, all moustached and gurning. The Gibson sting and valve amp thump of the opening bars of the title track leave you in no doubt that this is a proper working band, not just some novelty troupe of actors. When the horns come in for the bridge, it’s the first glimpse at what might have been had The Beatles ever bothered to do this kind of thing live themselves, as is the transition to ‘With A Little Help From My Friends’. “Ringo” is perfect, the scouse burr is faultless.

The orchestra isn’t as prominent as you might expect on the pleasingly trippy ‘Lucy In The Sky With Diamonds’, the heavy lifting is all done by the keyboards and the incredible bass playing of “Paul”. McCartney will always be, for me at least, rock’s greatest bassist – some might argue for John Entwhistle or John Paul Jones, or, God help us, some own-ass-inhabitant, noodling away on five, six, or even more strings – but it was McCartney who first unlocked the instrument’s melodic potential for powering beat music and it is this ceaselessly inventive lower stave work that drives every one of these immortal songs.

‘Getting Better’ and ‘Fixing A Hole’ are note perfect, from the guitar clang of the opening to the subtle backing vocals, and even include perfectly appropriate adapted endings to preclude the fade-outs you hear on the record. The combination of the orchestrations and the perfect “Paul” vocal mean ‘She’s Leaving Home’ is just beautiful. My only niggle would be the strum and pizzicato of the electric guitar, replacing the harp of the original, is just slightly too loud, but it’s a tiny complaint.

There’s a good chessboard visual gag – a reference to Ringo’s claim that he learnt to play the ancient game while recording the album – before we crash into the fairground nightmare-scape of ‘Being For The Benefit of Mr. Kite!’ Again, the keyboards do most of the work, although our “Ringo” proves himself pretty handy too. We then stop, to “turn over the record”, and a lengthy intermission, but the sight of ice cream hawkers going up and down the aisles to a soundtrack of The Pretty Things, The Kinks, and The Who seems strangely appropriate to the proceedings.

There’s another orchestral medley – ‘Tomorrow Never Knows’ sounds particularly good – and a gorgeous full arrangement of ‘For No One’ from the talented hand of Derek Cronin, conducted by Dr Crilly, who’s sporting a rather fetching Beatles jacket, and delivered by his accomplished charges, before side-two kicks off. Back when I was a young lad who didn’t know his arse from a hole in the ground, I would always skip over ‘Within You Without You’. I can’t imagine the album without it now. It’s one of the mesmerising highlights this evening as the tabla playing of Sandyman (Sandip Chakravarty) wades into the Gangean eddies of the strings under the sitar playing of “George”. It would have been the real Harrison’s birthday today; he’d tap an appreciative sandaled-toe to this.

There’s times for a reference to Thomas the Tank Engine, and a crack about an audience that’s more likely to be on antacid than acid, before an appropriate ‘When I’m 64’ It’s one of those McCartney songs that his detractors, Lennon included, scoff at, but there’s no disguising it’s melodic strength, complete with chimes and a nifty bit of country guitar. ‘Lovely Rita’ sounds like The Beatles you heard on parts of the Anthology series or the desaturated Let It Be… Naked from 2003, a slightly stripped back arrangement with acoustic guitars brought to the fore and close-your-eyes-and-it’s-them vocals. The horns on ‘Good Morning Good Morning’ get out of the way for the ‘Taxman’ style guitar solo and, yes, all the requisite farm animals bray and cluck us into the title track’s reprise.

If there’s one song that stands out from the original album, and perhaps stands out as The Beatles’ masterpiece, then it’s ‘A Day In The Life’. It’s the first song that came to mind when I heard the pitch for this show. The middle section, as the orchestra ascends through the discordant, cacophonic glissando, is almost apocalyptic, and the final chord, produced on the original recording by three separate pianos and a harmonium playing an e-major chord simultaneously, sounds like an avalanche. The song finishes with the four "Beatles" behind the bass drum, striking the pose from the record’s cover while the members of the orchestra don mask of the other cover stars. They get a deserved standing, stomping ovation.

After a brief interlude of more talk, they’re back for ‘Strawberry Fields Forever’ and ‘Penny Lane’. ‘Fields’ is a glorious combination of mellotron and swarmandal effects over cellos, although the orchestra could have been just a bit louder. The first half of the song takes on an interesting demo/Anthology-like quality as "George's" contribution is delayed to to a tuning mishap. The piccolo solo in ‘Penny Lane’ stumbles over its opening note, but no matter; these two remembrances of Liverpudlian childhood will forever remain untouchable. The strings are breath-taking on the Lewis Carroll/acid mixture ‘I Am The Walrus’ although the Stockhausen (he’s there on the cover), shortwave radio, King Lear quoting ending is absent.

‘Eleanor Rigby’ is hardly a Pepper-era track but it does give the orchestra room to work, and ‘Fool On The Hill’, never my favourite, is a delightful surprise. It reminds me, tonight at least, of those Beach Boys albums that arrived just after Brian Wilson started to fade, a descent prompted by trying to match Revolver and Pepper in the first place. The skilled work of the woodwind section deserves special mention. We finish with a sing-along to ‘Hello, Goodbye’, and ‘All You Need Is Love’, the multilingual placards and the musical quotes from ‘La Marseillaise’ and ‘She Loves You’ all pleasingly present and correct.

It’s marvellous theatre, and an unqualified success. Hot Press’ fifteen-year old certified Beatlemaniac of a daughter can barely stay in her seat throughout, such is her level of excitement, and the rest of the crowd are in a similar state. But, a cynic might decry, it’s all just pointless nostalgia. Look at it this way: the idea of Sgt. Pepper’s Lonely Hearts Club Band was conceived by McCartney, an unassailable genius at the height of his powers, in part as a look back to the British Legion bands of his youth, so it was a sort of throwback to begin with, but I am fast losing the run of myself here. Whether it be the fifty-first anniversary, or the five thousand and first, a work of art as complete and accomplished as this one warrants every celebration.

Hats off to both The Bootleg Beatles and the UCD Orchestra: close your eyes and it is indeed the act you’ve known for all these years.