Like any art form, classical music has its trends; one of them I’ve noticed recently is performers going barefoot. Manchester Collective’s music director and lead violinist Rakhi Singh often does so for vibrant string orchestra concerts; guitarist Sean Shibe has given a sockless rendition of Steve Reich’s Electric Counterpoint at the Wigmore Hall; a couple of years ago I saw Baroque specialist Richard Egarr lead the Academy of Ancient Music in a performance of Handel’s Messiah from the harpsichord with naked toes.

Among the ranks of the shoeless is violinist Patricia Kopatchinskaja, whose unique sound is raw and blistered as well as possessed of a ghostly beauty. Her exploration of the instrument’s more extreme terrain represents a different kind of virtuosity. As fearless about musical difficulty as she is splinters, her programmes embrace a gamut of challenging, expressively-intense contemporary and avant-garde pieces and builds them into adventurous theatrical concepts, such as Maria Mater Meretrix at London’s Barbican in 2023, with Ensemble Resonanz and soprano Anna Prohaska, which took in music from Hildegard von Bingen to Haydn and Kurtág. Daughter of a Moldovan folk duo, her performances have a freewheeling recklessness that both feel and are (in parts) improvised.

Her ongoing residency at London’s Southbank Centre has shown off the many strings to her proverbial bow, as dramaturg and actor, as well as instrumentalist; before Christmas she clowned about in Schoenberg’s brittle, hallucinatory Pierrot Lunaire. Dies Irae is her latest venture, joining with the Aurora Orchestra and Voices to create an unbroken 80-minute piece of orchestral theatre, boosted by choreography, adventurous use of the Queen Elizabeth Hall, projections, and a bit of dry ice.

She finds an apt partner in Aurora, who have made a name for themselves exploring these kinds of spectacles, performing works such Le Sacre du printemps and Berlioz’s Symphonie fantastique at the BBC Proms – all from memory, with actors and other scenic elements; next month they mount Hans Zender’s twitchy orchestration of Schubert’s Winterreise with tenor Allan Clayton at the Southbank Centre.

Dies Irae is intended as a piece about climate change – humanity’s Judgment Day – and was first presented at COP26 in Glasgow, but its expressive language is actually drawn from war poetry of one kind or another: Heinrich Ignaz von Biber’s Battalia for strings, a garish Baroque landscape of singing, stamping, and crying soldiers, interspersed with movements from American composer George Crumb’s Black Angels, a brittle, claustrophobic, electrified string quartet composed in response to Vietnam.

At one point, choppy footage of Hendrix playing the Star-Spangled Banner at Woodstock loomed over the players, acting as an intermezzo. Together with Crumb, Dies Irae borrows from one countercultural moment to articulate the ecological anxieties of the present; both are joined by horror in the face of wantonness and inhumanity, as well as being epoch-defining struggles for the future. It is an apt choice of repertoire: climate catastrophe will entail wars of its own, as states fight it out for scant resources and terrain. In the penultimate sequence of the show, a performance of Galina Ustvolskaya’s Composition No.2 (Dies Irae), the projections above the stage slowly zoomed in on the cracked, desiccated surface of a riverbed.

Hendrix is also a handy cipher for the knife-edge experimentalism that Kopatchinskaja champions, whether in Crumb, whose music calls for all manner of buzzing, rattling, and screeching, Giacinto Scelsi (whose guttural Okanagon, from 1968, for tam-tam, double bass, and voice rasped over the speakers as we sat down – a shame not to get the whole arcane ritual live) or indeed Biber himself, whose music imitates the uncoordinated drunk singing of soldiers, as musicians place sheets of paper between fingerboard and strings to sound like a snare drum.

Battalia is a piece presented with varying degrees of extroversion, turned up all the way to 11, both musically and theatrically, by Aurora and Kopatchinskaja. The rough-hewn opening gave way to a raucous party with a procession of upstage revellers joining the fun – good times before the end of the world, gradually soured by Crumb’s nightmarish visions of war and death. ‘God Music’ from Black Angels saw a recitative-like cello solo delivered from a platform upstage shrouded in haze, accompanied by tuned water glasses played with violin bows – their shimmering harmonics turning our eyes from the battlefield to the stars (shades of Olivier Messiaen’s glimpses of the beyond).

These moments of consonance, indeed unearthly beauty, were snatched away by the musical dramaturgy. A literal coup de théâtre followed the climax of PatKop’s – her composing name – furious micro-showpiece for violin and ensemble Die Wut, with Aurora Voices suddenly rising from among the audience to sing Lotti’s unaccompanied Crucifixus with a jewel-like gleam. Its final chord was disturbed in turn by the sudden invasion of a troop of trombones, roaming among the audience and blaring a single unison note – a rough funeral rite for the wounded musketeer depicted by Biber. The string players had sunk to the floor, picking up a muted version of the trombones’ grim threnody, which slowly bloomed through improvised passage into Dowland’s lute song Lachrimae antiquae novae, arranged for strings.

The show concluded with Ustvolskaya (1919-2006), whose music you listen to when you find Shostakovich too cheerful. Composition No.2 (Dies Irae) is scored for eight double basses, piano and coffin. The latter is a wooden box with a dry, dull resonance and wincingly noisy surface, thwacked with hammers. The bass players carried it on their shoulders – the funeral promised earlier by the trombones. For this, Kopatchinskaya finally took her shoes off. Michael Wendeberg, at the piano, prefaced it with a whisper of eerily elegant Bach.

Composition No.2 treads with forbidding determination for nearly 20 minutes; its circling material and almost unchanging pulse wear away at your sense of time and structure. The subtitle suggests its mood rather than any musical quotation. It sounds like a Mark Rothko painting: absorbing, endless, and with odd interminglings of monumentality and delicacy. The double basses often perform straining music in their highest register, which makes them sound like frightened dogs barking. The focal hammering point gives the whole thing a ritual quality, though its meaning is oblique. There are moments of uneasy lyrical warmth, just as in Rothko’s pictures: tender brushstrokes that fringe the abyssal rectangular forms. When they’re not grinding away, the basses emit an exhausted sigh; sometimes the piano will feel out some tentative chords in the middle register, rationing out the last expressive crumbs; even some of the hammering is surprisingly inward, sounding almost meek and pathetic. Any residual warmth is the glimmer of light from a dying star. Composition No.2 is a piece whose cold obliquity represents the indifference of the forces like climate change, which may well leave us in a very empty world indeed, after the deafening hammer of catastrophe has struck its blow.

The plainchant promised by the billing closed the concert, couplets exchanged between upper and lower parts. Aurora Voices filed back in with lamps and metronomes, along with the rest of the instrumentalists, similarly equipped. The chant circled as the metronomes ran down – an unadvertised riff on György Ligeti’s Poeme Symphonique, bringing out the mechanistic brutality of that piece – and the lights went out. Eventually we were left with Pat Kop and her intensely ticking machine, which she silenced herself.