With his willowy frame and unruly black hair, Robert Ames cut a ghoulish figure behind the translucent screen that separated him and the London Contemporary Orchestra from their audience at the Barbican. Appropriate, considering the date. But Halloween was not the subject explored in this potent combination of music and audiovisuals. Instead we were reminded of something far more terrifying: the imminent threat of global warming and its effect on our planet. 

Whilst aesthetically very different, it was this theme of mass destruction that linked the two works in the programme. Giacinto Scelsi's Uaxuctum – which received its UK premiere – is subtitled "The Legend of the Maya City which they themselves destroyed for religious reasons", whilst John Luther AdamsBecome Ocean vividly paints a world swallowed up by the irrepressible rise of the seas. His note in the score reads: "Life on this earth first emerged from the sea. As the polar ice melts and sea level rises, we humans find ourselves facing the prospect that once again we may quite literally become ocean."

What struck me first about the performance was the extraordinary technical ability of the LCO and the chorus that accompanied them for Uaxuctum. It is no coincidence that Scelsi’s magnum opus last night received its UK premiere. The five-movement work, scored unusually for six double basses, a cadre of percussionists, two tubas and chorus, is loaded with musical booby traps that ensnare all but the most skilled of musicians. 

Scelsi’s obsession with microtones, extended vocal techniques and the manifold timbres that can be produced from a single note, are explored to ghostly effect, and the performers did exceptionally well to recreate his remarkable soundworld – one of instability and impending doom. The addition of the ondes martenot – an instrument championed by Messiaen and played masterfully last night by Nathalie Forget – added to this sense of tonal ambiguity, dancing between pitches and evoking the other worlds alluded to in the concert’s title.

Become Ocean inhabits a seascape rooted more firmly in tonality, making separate but equally virtuosic demands of its performers. Its mammoth single movement depicts the relentless swell of the sea through a palindromic series of crescendos and diminuendos, waves building to a earth-swallowing crash right at the heart of the piece. 

An awesome feat of concentration was required from harpists Vicky Lester and Valeria Kurbatova, who combined their unrelenting ostinati to beautifully depict light refracting off water. And also of pianist Katherine Tinker, whose 7-note theme, played deep in the belly of the piano’s lower register, provided the inexorable core to the 40-minute work. Ames was excellent in bringing Luther Adams’ watery vision to life, never faltering in his passionate undulations of the baton, which in themselves depicted the swash and heave of nature’s pure ablution.  

The second thing that struck me during the performance was its often strained commitment to style. Not so much in the performers themselves, but through the addition of macabre audiovisuals that, using an AI algorithm, responded to the music. An interesting effect certainly, but with a novelty that had all but worn off by the interval. In Become Ocean, rather than enhancing the music, I felt the screen added a layer of distraction between players and audience, making it harder for the two to connect. This more cinematic experience was magnified by the thick reverb added to the miked ensemble, which, whilst boosting the spectral ambience, for my ears clouded the subtleties within the texture, and meant that only the very top and bottom ends could be heard clearly.

When the boundaries between live performance and the digitally re-mastered are blurred in this way, it makes the purists among us wonder if there was any need to make a trip to the concert hall. But perhaps that’s a little glib, and as the emphatic reaction from an encouragingly young audience reminded me, there was much to be applauded in this fascinating foray into the apocalypse.