For her ongoing series Occam Delta, the French composer Éliane Radigue (b.1932) has collaborated with various performers, marking her shift, this century, from mainly electronic works to music for acoustic instruments. Occam Delta XV (Actuelle) is dedicated to Quatuor Bozzini, who premiered it in Montréal in 2018. Radigue’s music is about constant flux: sounds that appear unchanging yet shift almost imperceptibly. The business of listening is part meditation, part heightened concentration, or “hyperconsciousness”, as the liner note explains it. Out of long, sustained chords, a whirr of microtones and harmonics eventually become audible. The process offers a powerful antidote to our short-attention-span world, if you can take it. Switch your phone off and spot the difference between two different versions, performed live and played with dedication by the Bozzinis.