For Christian Wolff, the point is specifying to performers not what should be played but rather how to play. Wolff, now 74, is the last surviving member of the New York School of composers, that loose association of like-minded individuals grouped around John Cage who had radically different notions of how chance and indeterminacy might revolutionise their art. Too much contemporary music hides the paucity of its ideas behind a veneer of complexity – in Wolff’s music, complex ideas are filtered into a musical surface that rarely breaks into a sweat. It’s a bewitching way to make art.

The Tilbury pieces are cult contemporary classics that disperse beautifully heard scraps of material around a spacious canvas. The Miscellany is an evolving sketchpad documenting Wolff’s myriad techniques and obsessions. Liebner brings deadpan detachment and a resonant, tactile tone to this inscrutable, always fascinating, whimsical music.

But the most bewitching piece here is, arguably, Snowdrop (1970) which generates itself from that most fundamental of musical parameters: scales. Important functional notes are sieved out of some scales and attached to others, while elsewhere groups of notes are interchanged to create odd scalic hybrids. Because the process is so fleeting and catches the listener unawares, fragments of melody and halfremembered gestures mess with your imagination. A vaguely Baroque bass-line falls over: am I really hearing “put the kettle on” with a missing “Polly”, “For Sale” with no “Love”, or the “la, la, la” refrain from Kylie’s “Can’t get you out of my head”? Or are Wolff’s snowdrops snow-blinding my ears?