If you consider Morton Feldman to be a challenging listen then take it from me, you don’t know the half of it until you try to review his music on record. The scale of his structures is such that those usual failsafe modes of ‘classical’ music reviewing – relative tempi and equivalent moments between performances compared and contrasted – suddenly don’t count for much. Because not only is Feldman’s music long, it’s repetitive. But not like Terry Riley, La Monte Young or Philip Glass. Feldman’s ‘repetitions’ in fact might not be literal repetitions at all, and moment-to-moment comparisons become meaningless, impossible even, because definable ‘moments’ as such don’t really exist – instead, various melodic modules subtly rotate on their various axes but never reveal all of themselves at any one time, making the music hallucinate on its own being.

So let’s open with a basic statement of fact: this latest recording of Feldman’s 1984 For Philip Guston, featuring Carla Rees (flute), John Tilbury (piano) and Simon Allen (percussion), is very fine. Enough to persuade me to put my other versions – the California EAR Unit on Bridge; Julia Breuer (flute), Matthias Engler (percussion), Elmar Schrammel (piano) on Wergo – up on eBay? Not really, because Feldman’s music, as Tilbury suggests in his booklet-note, despite being painstakingly notated, occupies speculative terrain more commonly associated with free improvisation: open-ended structures working themselves out over time. ‘It’s about being, and doing,’ Tilbury writes. And you can’t know an improviser from one record – you need a bunch of their records to gauge how patterns change and evolve.

Recorded at the Huddersfield Contemporary Music Festival in 2012 under less than ideal circumstances – Carla Rees had a heavy cold and sucked on cough sweets during a scheduled break – recording engineer Sebastian Lexer has discreetly soft-pedalled any coughing and eliminated the join. And this is very obviously a live recording. The boomy, echoing acoustic of St Paul’s Hall in Huddersfield adds to the weighty ritual and is faithfully retained. And if you’re interested in the usual comparative recording schtick – this recording has a noticeably slower pace than the California EAR Unit but broadly falls into alignment with the Wergo set. But more pertinent is the intensity of sound-making, softer-than-you-thought-ever-possible piano riding caliginous flute meeting only-just-there mallet percussion.