The Vibracathedral project began in Leeds as a collaboration between UK experimental mainstays Mick Flower, Neil Campbell (now know for his Astral Social Club project) and guitarist Julian Bradley, who are all present and correct at tonight's performance at The Cube. Having seen a revolving cast of musicians pass through the collective's doors and a stream of often self-funded releases, 2014 has seen the first Vibracathedral performances for a number of years after its respective members began to focus on other projects.

Mythologised in my mind by such rapturous accounts as Julian Cope's review of their 2002 album Dabbling With Gravity And Who You Are, it was with both trepidation and excitement that I attend the gig, put on by excellent Bristol promoters Qu Junktions who also provided some free punch for attendees.

Support comes from Bristol's Foehn, who presents a fairly uninspiring set of obscurantist noise and angst-ridden lyrics, though the free-jazz clarinet solo towards the end is not without its charms. Hence as Vibracathedral Orchestra take to the stage, I'm sitting in a place between welcome and wariness - desperately wanting to enjoy some tantric drone, quite put off by the prospect of a set of discordant squall.

Turns out I needn't have worried; the Vibracathedral Orchestra live experience is both mind-blowing and genuinely accessible. It sounds a bit like the most abstract parts of your favourite psychedelic rock records flattened out and stretched into endless and ecstatic cod-raga jams. Their sound also takes the tenets of minimalism and applies a naïve, primitivist approach; the results of which come across like a deeply stoned children's orchestra interpreting a piece by Terry Riley. Reference to the Incredible String Band collaborating with Taj Mahal Travellers would also be on point, as would the assertion that the absence of linearity in Vibracathedral Orchestra's music makes it exist purely in a transcendent now that allows the listener to surpass their subjugation to linear time.

The group's piece opens with blasts of freewheeling wind instruments: recorders and a shawm overblown over an introductory drone – the importance of which is central to Vibracathedral Orchestra's effectiveness and accessibility. The most abstract and discordant moments in their music seem always to be backed by this single pedal note, an entry point for the listener from which the seeming randomness of the accompanying sounds can by appreciated. Jangling bells and insistent tom-tom beats provide the rhythmic flavor, whilst Neil Campbell's sawing violin inject a neo-Appalachian modal counterpoint. Julian Bradley's guitar lines are the most recognisably psychedelic rock-influenced aspect of the arrangement, strumming out repetitive two-note riffs that provided another anchor on which to weather the sonic storm.

Vibracathedral Orchestra's approach to improvisation seems a strange one, possibly having roots in the explosive traditions of free jazz rather than any rockist idea of structured jamming, but seeming on the whole to be pretty idiosyncratic. Each player seems to make noise constantly, in ways that avoid any sense of pattern or phrasing. Yet some coherence between the sounds and players allow for changes in mood, tone and colour occur almost without you noticing. Their music seems constantly to be moving but you can never tell how or where. You could enter the performance at any given moment and you'd be greeted with an inviting bubblebath of acoustic and electric sounds, at points building to crescendo to create a single euphoric hum. After about an hour the players all begin to shred together, creating an ecstatic blaze of noise reminiscent of Mick Flower's collaborative work with drummer Chris Corsano.

This, for me, would have been a fitting end to the piece. However staying true to their gradual methods, the group allow the noise to dissipate over another half an hour, moving further away from the drone and tonality as the sound devolves into squalling wind instruments and synth-noise. Whilst one of the more texturally interesting moments of the performance, it became at times quite excruciating in its trespass into the realm of skronk, the number of people around me checking their watches confirming that I wasn't alone in this feeling. However as the piece comes down to its denouement, rapturous applause ensues.