Photographs thanks to Shot2bits.net

James Johnston isn't just perspiring; he's practically pissing sweat. His black shirt, held together by a single button, is soaked through to the degree where it's clinging to his wire-thin body and the stage lights are reflecting beams from its wettest areas. Above his head – itself a matted mass of long hair that takes on a life of its own – are his arms, crossed at the wrists, which pump in time with his thrusting crotch. In the blinking of an eye, the guitar which has been slung behind his back is suddenly in his hands and waved this way and that as he coaxes filthy and grinding sounds from it. Here he is in full flight and the spectacle is nothing short of magnificent.

Few are the bands this far into a career that exceeds 20 years where new material reaches for new heights and pretty much exceeds what's gone before. With The Soul Of The Hour, Gallon Drunk has released arguably their finest album to date and one of the best of the year of any genre thus far. Their M.O. for the album saw the band jettison many of their characteristic calling cards – the saxophone, slide guitars and harmonicas – and the end result has found Gallon Drunk setting sail for previously uncharted waters with a voyage that is reaping huge artistic rewards.

Unsurprisingly, there's a palpable sense of anticipation as Gallon Drunk steel themselves and unfurl their set with the 10-minute epic 'Before The Fire'. As with its recorded version, the song begins to rouse and uncoil itself slowly and methodically but here the ever-strident piano gives way to Johnston's tremeloed guitar. A bold move to be sure and whilst one can appreciate the decision on a practical level as the sound is adjusted here and there, the song's ability to beguile, hypnotise and ensnare is undoubted. If The Soul Of The Hour can be seen as re-birth of sorts then this performance is a conclusive affirmation.

Bolstered by Ian White's disciplined and propulsive drumming and Leo Kurinis' low-end throb – a pulse so deep that it's a wonder that TFL haven't employed his services for the digging of the Crossrail link – Gallon Drunk's sound is given further breadth thanks to Terry Edwards' multi-instrumental skills that see him move deftly from keyboards to saxophone with a consummate and almost indecent ease.

Of course there are nods to the past in the shape of 'Traitors' Gate' and 'Killing Time' among others but it's the new material that truly lingers after the event having left its indelible mark at the time. 'The Soul Of The Hour' drips with menace and malevolence before exploding into a catharsis of violent sounds that take root in the head but the real high water mark arrives courtesy of an extended and thoroughly seductive reading of 'The Speed Of Fear'. Anchored around a swooping and circular riff blasted from Edwards' keyboards, the band locks into a murderous groove that increases with a searing intensity and allows Johnston to take flight both physically and musically.

Emitting the kinds of high level fuzz that would bring a smile to Link Wray's face, Johnston twists and turns across the stage as his guitar finds its way behind his head, in the air and back home again. This is a breathtaking display and one that sees them breaking away from the song's roots as it gives way to a free jazz freak out redolent of The Stooges' 'L.A. Blues'.

A staggering performance of incredibly intense music, Gallon Drunk are absolutely on top of their game and are deserving of a far, far wider audience.