Morton Feldman wasn’t one to over-indulge in theory. All the more interesting, then, to read a note on a sketch unearthed at the Paul Sacher Foundation: ‘This piece is just the outline of becoming. It can start anywhere, go anywhere within these references of sound.’ As Ryan Dohoney shows, this came from Feldman’s reading of the French vitalist philosopher Henri Bergson. While it refers to an early open-form work, it’s a fitting image for Feldman’s later works: beginningless and endless forests of musical sound.

This disc of two later orchestral works doesn’t propose any radical new perspectives. Coptic Light, Feldman’s final work, is already well represented on disc; String Quartet and Orchestra, only available on one previous recording, is the draw.

Coptic Light was named for the ancient Coptic rugs with which Feldman felt artistic kinship. A half-hour polyphonic weave of figures and filigree, Coptic Light opens by orientating around the smallest figure, a perfect fourth descent and return, repeated ad nauseum on violins with small occasional variations. Orchestral balance must ensure the many simultaneous figures – sustained brass dyads, broken piano chords, low ebbing strings – remain coherent. The ORF Vienna Radio Symphony Orchestra give an admirable reading under Michael Boder: simultaneously transparent and lointain, if at times too muted in some details.

In String Quartet and Orchestra, brief lyrical fragments from the string quartet interact with static chords in the orchestra. As in Ligeti’s texture-based orchestral works, no momentary configuration overstays its welcome. A brief solo cello figure, a repeated descending semitone, is quickly replaced by a sustained woodwind cluster. But in contrast to Ligeti, the replaced figure is not gone for ever: a minute later the descending semitone figure reappears in a much higher register in the violin, this time accompanied by one of the cluster’s pitches sustained on trumpet, before vanishing in the resonance of a piano chord. If in the smallness of the gestures along with the inexhaustible permutation the music recalls Webern, it is in slow motion and stretched over a vast canvas. The Ardittis’ playing is fragile and unvarnished, showiness foregone in favour of Rothkoesque spiritual mystery.