Live: Titanic. Demdike Stare, Union Chapel.

Although gigs in chapels and cloisters have become ever-present and sought-after of late, 'the occult new project from Miles Whittaker and Sean Canty' that is Demdike Stare probably wouldn't be Union Chapel's go-to duo were they in search of a couple of new choirmasters. The pair's Facebook profile picture – a facet of a quasi-religious phenomenon in itself with a number of adherents disproportionately inferior to that boasted contemporarily by Christianity – manifests a deathly grim juxtaposition of life and death and indeed Whittaker and Canty are here for some downright desecration in place of deferential praise. However here, their sanctimonious atmospherics prove to be of purely divine variety.

Attracting an extroversive and extensive demographic that comes to include estranged Klaxons and more heavily weathered types whose "song of the sixth form" could be considered Mud's '74 single Tiger Feet, those that fidget restively in wooded pews are as richly individualised as the unholy palpitations tonight thudded out from the heart of Islington. As the pipes of an Amazonian interpretation of Scarborough Fair disintegrate into musty air, the pair emerge. Whittaker gazes upwards as if attempting to make out some supernal demiurge or at least the intricate ornamentations of the pillars that shoot skyward from lowly vantage point. A wonderful venue is this and so too is the opening barrage of ungodly static. Offset by visuals that look a little something like tea-stained white noise, heads are swiftly entombed in MacBooks as they're immediately down to business.

The segueing hour is then, almost exclusively via the medium of noise, equivalent to a Mephistophelean hurtle to the grave and beyond. With interaction kept to a minimum even between themselves (they sit a good few metres apart on a table all too titanic to fit even in the back of a hearse, only occasionally paying each other gentle glances as if unsure of the demonic power their own music beholds), the sound they peddle is afforded an overwhelming prominence. Although an AV show, its visuals are largely your standard fare of murky hues and refracted headlights, occasionally flaring up into inferno to rage above and beyond makeshift screen, thus all impetus and attention is piled onto the A to their flickering V.

And so how is the aural spectacular of Demdike Stare translated to this setting? Well, from humble stall it's inky industrial maelstrom that's irresistible to the point of helpless attraction. I'm sucked in from its opening swirl of menace like a sable nocturnal butterfly, prior to continuing to persistently thud cranium against throbbing invigoration for the remainder. It's a disconcerting comatose that feels precarious, brutal, unstable yet it's one I'm unwilling to awake from as static flows into snippets of odd harmony and utter abrasion, the sort of oracular shrills last splurged when Fennesz came to preach. The pair periodically lean into the tribal propensities one may expect were method purely deduced from moniker although it's when they keep things mean that I'm kept most keen for momentarily the sinister darkness they brew feels like having mephitic spray paint forced down forcibly agape gullet as part of some obscenely macabre ritual. Again however to modify such sensation would be to neutralise their devastating impact. For although invigorating and gripping and intense, these preternatural sounds and pulsations allow for personal, contemplative space despite their sunless atmospherics; as religion itself was perhaps once intended.

Just as with any form of interaction, applause too is kept to a minimum with only three bursts denoted throughout. Whilst in many instances this may serve to dislocate artist from audience, it feels as though a unity is bred within as we all share in one transcendental experience having gorged from the same unspeakable chalice. Intoxicating and transporting, the lifeblood of the evening is barely in keeping with any form of earthly relevance: in contrast to the grim realities, the "Es and Wizz" entailed of many a Saturday soirée within this groggy, depraved metropolis we've come to know and recognise; love and loathe as London this pseudo-diabolism feels both pure and purging; human or at least familiar and yet entirely obscure. Much to the same extent, boundaries are pushed in terms of Demdike Stare's musical method as analog wrestles with digital as it's laptops versus vinyl, deathly screeches incurred every once in a while as the needle is jarred down on unsuspecting LPs lingering below. It's as though Canty vampirically thirsts for blood to be drawn from phonograph record as he stabs at them insistently, his face purveying the pacific vitriol of Patrick Bateman.

For two men, two laptops and an inexplicably potent projector to grasp every fluctuating level of concentration as such is as intriguing as every punctiliously constructed scripture and departing all too punctually without a word of thanks nor an equivalently monosyllabic comment, they remain as enigmatic as that aforesaid Almighty Whittaker once gawped up toward.