Much like music, dance has evolved far beyond its founding building blocks. Neither rhythm nor melody lie at the core of much modern 'music', which is now assuredly a term broad enough to take in all manner of sound-as-art. Likewise, dance has eschewed its founding skeletal confines within the boundaries of the beat, ancient traditions, and the visible spectrum of bodily language. British choreographer, Wayne McGregor, along with his company Random Dance, have careened headfirst into arrhythmic expressive forms of dance, attempting to work outside of the medium's established spectral range. It's a continuation of post-everything's gradual ubiquitous inception. As popular culture crosses into a singularity, where everything will ultimately become everything else, the 'high' arts (i.e. expensive stuff that happens in well-funded theatres and galleries) tiptoe similarly on, and works like Atomos are the result. Ten dancers prancing in unrecognisable patterns, interlocking and jarring in equal measure, tickle the brain to search through its files of cultural signifiers, trying to discover where Atomos belongs - only to come up empty handed. How do you provide a score to such activity?

The duo of Dustin O'Halloran and Adam Wiltzie first got together having both escaped the cultural wastelands of America for a brighter life in Europe. Dustin O'Halloran had eschewed his roots in West-Coast dream pop group Devics, focusing on his piano playing, and making a name for himself as a film composer for the likes of Sofia Coppola. Adam Wiltzie had similarly moved somewhat on from his legendary drone outfit with Brian McBride, Stars of the Lid, and thus the first A Winged Victory For The Sullen's self-titled debut album was very much a combination of Wiltzie and O'Halloran's music identities. The former's effect-laden guitar atmospheres made a bed, onto which O'Halloran tinkered slowly-pronounced piano chords and melodies, evolving themes into dreamlike epics, augmented with woodwind, brass and strings from such neo-classical scene regulars as Hildur Guðnadóttir and Peter Broderick. With their score for Atomos the pair have certainly evolved as composers, broadening their own individual pre-established palettes of sound, while trading any woodwind or brass for a dedicated group of closely collaborating string players from Wiltzie's adopted home in Brussels.

As detailed by the duo in a recent interview I conducted with them for the Quietus, Wayne McGregor's influence over the piece was pointedly distant and minimal, suggesting themes and aesthetics, but leaving almost all of the structure, sounds and actual music down to the composers to complete. O'Halloran described how "Wayne sent [them] these photographs and films for inspiration," and that "ATOMOS is actually based on the formation of atoms, and outer space". While such a blank canvas has definitely led to a work whose actual meaning is ultimately open to much interpretation, the organic logic of atomic science, and the colossal movement of heavenly bodies could aptly describe much of the score.

The immaculate recording, completed with the assistance of Ben Frost and Francesco Donadello, sets the scene in a cavernous space, which is increasingly revealed as the piece's various melodic strands enter and leave proceedings, with countless spiralling string arpeggios surrounding the listener through dozens of peaks and troughs. The most immediate evolution from their debut, is in O'Halloran and Wiltzie's ability to place themselves firmly in the passenger seat when necessary. Atomos II starts and ends with chiming bell-like synths from the duo, but is chiefly built around a rhapsodic cello line that pulls in the surrounding violins and viola for one of the score's most immediately beautiful passages. Similarly, the final Atomos XII is in fact features neither O'Halloran nor Wiltzie - in live performances they both leave the stage at this point - and instead revives the opening keyboard theme from the piece, reimagined in a variation solely for strings, and all played out atop a ringing violin ostinato. Emotionally, it's about as powerful as this sort of music gets, while the cyclical scraping of strings irrevocably evokes images of bodies in motion, reflecting the abstract flailing of McGregor's choreography.

At times, the music revives territory that's perhaps too familiar for some. Atomos V is essentially a four-minute crescendo, building bar-length string notes to a luminescent peak yanked straight from Sigur Rós' soppier catalogue, while the O'Halloran piano figures at the core of Atomos III are totally reminiscent of the first Winged Victory album. For the most part though, it's actually incredibly fresh new ground, most audibly in the presence of discernible rhythms. The pair have described how McGregor made it clear that this being for "dance" in no way meant they were required to insert rhythm into the piece, but the constant presence of arpeggiated keyboards and string ostinati ultimately come to define Atomos, and it's all the better for it. The centre of Atomos VI pulsates over a jutting rhythmic synth pad while the ghostly beginnings of Atomos VII eventually succumb to repeating bass tones. Atomos VIII is where the arpeggiation fully kicks in alongside grinding organs in a repetition that assumes the form of a sweetly winsome take on pulsating Klaus Schulze kosmische circa Time Wind.

In the field or contemporary classical music, or ambient classical, or drone, or whatever we're supposed to call it, both listeners and musicians a like often namecheck the likes of Estonian minimalist composer Arvo Pärt, Brian Eno's Obscure records label, or (sigh) Steve Reich/Philip Glass. While the likes of Pärt's intertwining strings on 'Tabula Rasa', or the sonically treated strings on side B of Eno's Discreet Music bear some passing superficial resemblance to ATOMOS, the approach of Wiltzie and O'Halloran to structure, and their alchemical use of keyboard and effects pedal synthesis put them in a wholly different, aesthetically-centred category.

In total, the score of ATOMOS is perhaps even more compelling than anything either half of A Winged Victory For The Sullen has done before. The project's sheer scope, and McGregor's blank-canvas instruction have broadened both Dustin O'Halloran and Adam Wiltzie's own musical toolboxes significantly. The ensuing apocalyptic breakdown of the keyboard noises in Atomos X, and the decision for keyboards and guitar to remain entirely absent from Atomos XII are both sure signs of both maturity, and the acceptance that a musical journey can just as easily detour towards dissonance in the name of a greater whole. ATOMOS is certainly a sensitive and thoughtful piece of work on its own, but the ultimate success of the listening experience is in its ability to stir an emotional reaction, and impose a state of thoughtfulness on the listener - and presumably on the dancer too.