Nearly twelve years ago I was in the audience for Rhodri Davies giving the first performance of Éliane Radigue’s Occam I for prepared harp, little suspecting the proliferation of acoustic pieces that would follow in the series. I’ve blown hot and cold on them ever since that equivocal premiere, having heard various Occam iterations for solo, duo and larger groups which I found either intriguing, technically interesting or just rote. Occam Delta XV, composed for the Quatuor Bozzini in 2018, is the first Radigue piece that’s got me really enthused since hearing her Naldjorlak trilogy at that same gig so many years ago. While Naldjorlak creates awe through its sublime, immaculate surface, Occam Delta XV is far more turbulent. The drones that make up Radigue’s compositions have always been in constant motion, but this string quartet draws on an inherent complexity in the material seldom heard since she abandoned the use of analog synthesiser. A lot of that can be attributed to Quatuor Bozzini, too. Radigue taught them the piece orally and their peculiar quality of playing — making music sound both very new and very old all at once — comes to the fore here. Two performances are presented here, recorded live on consecutive nights in late 2021. It’s a piece that depends on communication and mutual feedback between the four musicians to guide its progress, and so the two versions vary greatly, with each sounding more like a studio creation than a live gig. In the first, variations in the bowing produce a handwoven, folk-like aspect to the music, stretched and suspended into watery, wavering overtones like a Canterbury hippie’s pastoral reverie. Pitch material varies over the course of the piece, thickening into a dense passage of multiphonics while transforming further and further away from its tonal origins. From the second night, things are calmer but darker, thinning out into wisps of harmonics before ultimately resolving in more conventional fashion. I wonder if other quartets could produce astonishing results from this piece, but I suspect they would be very different from the Bozzini.