Live: Ascension! Godspeed You! Black Emperor, The Forum.

"Remember remember the fifth of November;
Gunpowder, treason and plot.
I see no reason why gunpowder, treason;
Should ever be forgot..."

The fifth of this given month, I ought start by saying, is a date I have little trouble recalling, for it just so happens to be my birthday. Always has been. A time of celebration, therefore; of unnatural explosivity. Yet whereas many see theirs off with a bang to the bombast of damp chart fodder, I thought I'd opt for the slow-burning majesty of Godspeed You! Black Emperor, alone, down one of the darker parts of London. Although perhaps not the archetypal birthday band (were such a construct to exist, for the benefit of convincing argument) Efrim Menuck, Mike Moya et al. have recently rekindled the passion ever asmoulder within their every staunch acolyte with the quasi-clandestine release of 'Allelujah! Don't Bend Ascend. Slipped out onto a Boston merch desk at a stateside showing just last month, the stench of suspicion may have already been rife, for these dates were traced out in gunpowder long ago. Though the record didn't so much alight our collective ardency, as torch our hearts for it is arguably their most intense, igneous, and entrancing release to date. And yet despite this being only the routinely subversive Montréal troupe's second UK showing since, they barely touch upon its still blazing resplendence.

I've oft contemplated this concept of the birthday band, though, particularly in the approach to this particular show. Just this morning I tore at wrapping ensnaring And the Ass saw the Angel and whilst a read I've long since been meaning to scan, The Birthday Present certainly aren't such a band. I once saw Mike Patton's smutty Peeping Tom side-project over in Brixton upon this fated date and shivery unsightly as he may have been in a cranium-encasing hair net, that show wasn't ideal either. Still, self-professed 'hollerin' brothers and musical magpies' Dead Rat Orchestra inadvertently come kinda close. For this side of the Lebanon, few unknowable, ethnically hemmed experiences could better accompany the ushering in of a faintly terrifying two-four than the Colchester-via-Madrid ensemble.

Clustered about a couple mics, a plank, and a harpsichord the trio reconstruct semi-imagined fragments of Faroese music, and interweave these with beardy bristle, antiquated Norfolk folk dirge, compelling Gallic jigs, and rickety sea shanties in an anarchic mosaic of musical history. Huddled stage-left, for music quite so entrenched in conventional histories theirs is an off-kilter proffering that draws upon influences from far and wide, with Celtic stylisation infused with something Romany almost, to combine in something altogether romanticised. Just as we strive to daub every memory with a veneer of nostalgia, the 'Orchestra thereby appear to aspire to renovate musical relics inherited by the contemporary in order that they may thrive in this now. They're an odd fit when placed alongside Godspeed, but then the way in which they lull us into a soft state of respite calms as may verdant leaves in a peppermint tea that quiver prior to tumultuous storm.

Though the troupe's own collective histories already span a quite considerable period: they've been working away at this for a decade now, and it shows. Not in the profound creases and pained expressions smeared across their faces, nor in the length of their wibbling facial prickles, nor even in their recalcitrant, malfunctioning instruments. But in the way they allow their set to intensify, only to subside before bringing it to an acute crescendo as it closes in a decomposing mantra of possessed incantations. These come spat, more than owt else as the three combine in one to seethe a yodelled disdain, mimicking the forsaking of an unfaithful daughter seated deep in days of yore. Kids, too, are another theme braided into the fabric of the band, for as time has continued to tumble onward, they've discerned their own becoming increasingly expensive.

Thus if you've shrapnel, I'd implore you spare them a ha'penny or two. For it's "with joy and sorrow in our hearts" that we bid them adieu, as there's now but half an hour to shield us from the cruel maelstroms of Godspeed. The Dead Rat's half-hour has pertained to the sheathed grandiosity of a cinematic trailer – the sort to only exacerbate impatience, as we wholly anticipate the main event. And it's one we expect to blow the night wide open with a silvery, widescreen boom.

Barbed drones and whiskered harmonies interchanged with unintelligible babble, an inert ambience starts to brood in the in-between. One of only slight agitation, it's one for the 'Black Emperor to maul.

At long last, as has now become customary, one by one the ensemble emerge. They take their places, swill from their strategically scattered bottles of bloody rouge, and bespoke live intro Hope Drone begins. Strings clang, statics rage, and indeed within moments we're left to feel as though all earthly hope has been snatched forevermore, never to return. If the stupefying shock of 'Allelujah!'s impromptu release is still to sink in, then this is an almost overly impactive live reawakening. It's the sound of domesday squawking as sheet upon sheet of raven-black smothers the sky. I'd say it were beautiful, were it not so soul-ravaging. But its fuzzy hums only magnify with time, a mien of concerted exertion and undiluted emotivity indelibly drenching their every face. Concentration never seemed so pure.

And then, abruptly, this dissonant symphony turns a corrosive tone. It becomes Mladic. Visuals of sepia-doused, scratchy celluloid start up, buffeted about by squalls of commensurately abrasive scrapes of coarse string. The opening minutes of this, 'Allelujah's opener and its only track tonight aired (coincidentally, it happens to be the finest of their latest four, and their finest composition in over a decade therefore) feel an ordeal with all pejorative connotations abraded, as it takes what feels an aeon for it to become in any way recognisable. Eventually though, at least five minutes in, it all begins to come together. Faint harmony in disharmony; creeping hope in an all-pervasive hopelessness. Positivity flickers for one fleeting moment, before being promptly devoured by the most almightily guttural barrage of primordial rhythm and Asiatic riff, each note towering as though a monumental apex; the prick of the pyramid. Hooded figures stalk the back shadows, as the sense of the cinematic seeps into waking reality.

Again, however, intensity serves as a keyword. I've always found it somewhat startling that Godspeed therefore perform seated – it lends an outward aesthetic of casual insouciance, and Menuck too tends to stroll onto the scene minutes in to Hope Drone. But with the emphasis of the live show now so focussed upon the atonal – with Karl Lemieux' hand-operated projectors reeling off a visual disquietude to compliment this consummately – it may now be necessary to prevent the eight-piece being hurled to their hands and knees by the sheer ruination of it all. Mladic is afforded the effect of actuality-splintering annihilation that could only otherwise be achieved were the record groaned through the Grateful Dead's Wall of Sound, as it is transposed into highly volatile, incendiary post-rock. Its architects remain workmanlike – heads down, glum in unremitting expressionlessness, and enshrouded in shade.

These are intimations of abandonment; of a Hadean nothingness filled with an uncontrollable malevolence as all intensity is augmented by a deficiency in both pause and interaction with their public. Though Mladic whirs its forceful, compelling groove and allures to the verge of the inviting. It buzzes and snarls for quite some time as heads roll limply in unison, before it fades brusquely. And it's this manipulating of all things staccato that has long since set Godspeed apart. For whilst much of their musical outpour may be lumbered in with the great pyres of lugubriousness to litter the genre, each piece is markedly refined; remarkably defined. The hushed openings of Moya are spun along by Lemieux' hurrying reels perched at the rear of the stalls, with the visuals they spew of trains in reverse exacerbating the overwhelming sense of distance and loss conjured, primarily, by Sophie Trudeau's woebegone strings. They seesaw on pivots of quavering bass resonances, as all around fanfares blare and snares rattle and clatter like heavy-duty freights.

It's Behemoth, though, that forms the night's monolithic centrepiece – droning and faint, as though a subtly baleful field recording recorded at the heart of a barren hinterland. It's of a vague nowhere between a gelid easternmost Europe and a more exotic Orient, and as ever elucidates the troupe's nonpareil control of static and feedback as bows singe cymbals that in turn shriek industrial omen. They are as though struggling for breath in Siberian wastes, but Godspeed are the superlative sorcerers of such wild, mercurial sounds, and they too are their tamers.

Alighting at a proggy space-out that's abetted by perception-spasming, retina-lacerating eye forage its inclusion explicitly illustrates that which has been intimated for some time. That as they age – and mature exponentially, with that – the dolour once innate of their every work is waning somewhat. For beyond the ascendant slide guitars resides the sound of distant, yet still discernible celebration. Indeed grizzly interludes aside, there's great cause for celebration as the five tracks selected serve as a commemoration of a thoroughly inspiratory collective career, with splodge-infested footage of the four walls adorning 'Allelujah! sleeve – walls here overlaid with an opaque crackle – functioning in coalescing the show into one lone whole.

It's a lonesome whole that, though it may drift in and out; out and in of focus as dooes a derrunk, keeps us both rapt and snuggly enwrapped in a leaden cloak of melodrama. Though every emotion known to the sentient being is encapsulated in Blaise Bailey Finnegan III, as it sweeps in unsuspectingly only to end in a rasping blurt that sounds akin to Kentish Town purging its every immortal sin at once. I'm stood motionless; awestruck, as though observing and memorialising plucky martyrs trudging valiantly off into the final moments of this world. I'm left feeling strangely proud, and it's all irrevocably triumphant. Solemnity does of course continue to reign supreme in this realm of the sensorially overpowering, and as the troops dump stuff, don coats, and depart in accordance with the reticence with which they came, their sonorous feedback continues to crackle and hiss long after their passing.

A few brutal minuten then pass, before Tim Herzog materialises to power down the pedal armada, allowing for some soft psych-jazz to parp up. It's pretty inappropriate, though what it does do is augment that inescapable sense of the inimitably ATP. Which is, ultimately, an ambience I long to inhabit every day, of every year, for all eternity. It makes reality all the more mundane, as any memorable birthday ought. And Godspeed just thrust this one right up there.