If a Samuel Beckett and Morton Feldman double bill sounds forbidding, evidently word hadn’t reached London’s Queen Elizabeth Hall back in November, which saw people turn out in droves for two inordinately demanding experimental works. The London Sinfonietta, who filled the same hall with a focus on the tricksy, ingenious music of György Ligeti in autumn 2023, turned their attention to these two giants of 20th-century modernism, joined by students from the Royal Academy of Music – the Manson Ensemble – and the Trinity-Laban Conservatoire of Music and Dance, with conductor Jack Sheen and stage director Rowland Hill, drama and music placed side-by-side.

Beckett’s Quad began life in 1982 as a commission for Süddeutscher Rundfunk under the title Quadrat I + II. A piece for four players, light, and percussion, it is cast in two parts, and originally conceived for television, along with other late, concise works by Beckett, such as Ghost Trio and Nacht und Träume. Quad II presents a ‘variation’ on the first, at a slower tempo. The four figures are in hooded, full-length coloured robes, which conceal their faces and genders (‘As alike in build as possible… sex indifferent’, writes Beckett), moving across and around the titular square according to precisely choreographed movements, against a ‘constant neutral light’. In Quad II the formal restraint tightens even further, with all four figures wearing white costumes. It has the restraint and formality of a Japanese Noh play, and has the same ritual, inward austerity, which also applies to Beckett’s drama.

Purely choreographic, Quad has no dialogue. The elimination and excision of words from Beckett’s terse later works reveals the importance of music in his theatrical imagination, a spectral presence where speech once was. The taciturn Ghost Trio borrows title and excerpts from a chamber work by Beethoven. ‘Mine is a faint voice’, the female speaker begins, ‘kindly tune accordingly.’ Musical puns proliferate as we are told of ‘the familiar chamber’. The faltering monologue of radio play Cascando (1961) has its elliptical words supplemented by a musical underlay, composed by Marcel Mihalovici. The title is an Italian musical term that describes dissolution of both tempo and volume, with speech and music winding down to an inevitable Beckettian silence. Nacht und Träume, created like Quad for SDR, takes its title from a song by Franz Schubert and gives a fragment of the Lied the last word. Beckett was captivated by Schubert’s Winterreise, whose processional gloom seems to anticipate the blasted imaginative landscapes of his work in its bleak psychopathology.

The rapid, beating footsteps of Quad provide one of the play’s sources of energy as the figures pace around. They bounce off a central, circular beam of light, labelled ‘E’ in the script; ‘supposed a danger zone’, Beckett writes. Contradictory impulses of attraction and repulsion, whose countervailing energies create a kind of frozen, immobile tension, are fundamental to Beckett’s work, whether in the apocalyptic housemates Hamm and Clov in Endgame or Vladimir and Estragon’s predicament in Waiting for Godot (‘Yes, let’s go’, the latter advances; They do not move, Beckett notes.) Quad’s missed connections, whose encounters appear increasingly chancy as more figures join the dance, stages this dynamic with the utmost formal economy, beautifully realised by intensely-pacing students from Trinity-Laban. It was absorbing and beautiful.

Coming from the wings there was the quietest shimmer of untuned percussion, each dancer given their own corresponding timbre as they appear – wood block, snare drum, triangle, gong – which also suggests this animating tension. It could’ve been less subtle, if anything – I couldn’t make out the percussionists, who Beckett specifies should be ‘barely visible in shadow on raised podium at back of set’, and nor was the beginning and cessation of sounds that are supposed to signal the dancers’ entrances and exits all that clear.

Alongside the percussion instruments allied to each figure, there is also the sound of their own footsteps; Beckett had previously built the quasi-musical structure of 1975’s Footfalls around the metronomic steps of the central character. This fifth percussive instrument, situated in the body, might suggest a parallel with Steve Reich’s minimalist masterpiece Clapping Music from 1972, albeit much more austere and mysterious than Reich’s virtuosic recollection of Flamenco for two performers. ‘Each player has his particular sound’, writes Beckett; an imprint of irreducible human distinctiveness on Quad’s otherwise impersonal schema, though I can’t say I heard much difference – though perhaps it is an impossible theatrical demand, doomed to the artistic failure that Beckett so prized.

In such an austere work, detail is everything. The central spot could’ve radiated more brightly, as the white-hot no-go zone around which the work pivots; costumes were cut a shade too long, and nearly saw one dancer trip up (well recovered); they were also marginally too figure-hugging, sacrificing some of the androgyny Beckett calls for in the text. A long pause at the start of the performance also puzzled – perhaps the intention was to get the audience into a state of alert, quiet concentration, but this was stymied by the house lights remaining up throughout, encouraging people to fidget and look around as if they are waiting for a wedding to start. But what a treat, nonetheless, to see this cool and compelling rarity from the playwright.

Morton Feldman’s late chamber works are vast structures, punctuated with abyssal silences. For Philip Guston, a 1984 trio for flute, piano, and percussion dedicated to the great painter, lasts over four hours. His String Quartet No 2 clocks in around five-and-a-half; the composer Julian Anderson recounted to me once Feldman dozing softly through its 1984 UK premiere from the Kronos Quartet on a sweltering hot day in the library of the Reform Club.

At around 50 minutes or so, For Samuel Beckett is a miniature by comparison, though its precipitous approach to beginning and ending means that it captures the same time-obliterating aspect as his other works. Feldman’s ensemble is created from layers of woodwind, brass, strings, and piano and vibraphone, the last two sounding their inbuilt quality of decay. The ensemble’s overlapping chorales barely rose above the softest dynamic, sustained with miraculous discipline and finesse throughout by conductor and instrumentalists. The loudest noises we heard in the concert were someone dropping their bag as they left and a phone which rang uncannily in tune with the harmonies – markers of an outside world that had come to feel utterly estranged from Feldman’s musical one.

These musical layers overlap, but do not coincide, rather like the figures in Quad who both attract and repel. These friezes suggest a form of musical parataxis, just as Beckett would do in his vast theatrical monologues or multi-clause pile ups of his prose, whose elements run in parallel but are not necessarily coordinated or complementary; lining them up is left to the eye and ear of the audience in both cases.

Feldman’s musical material is continually and microscopically varied, like the prose in Beckett’s The Unnameable, in a constant play of repetition and difference; he got the idea from the way the patterns in 19th-century Turkish carpets were made. This is not however experienced or understood as a ‘development’ that you would hear in a symphony by Brahms or Beethoven, consequently imbuing it with a feeling of departure, arrival, adventure, and return: musical prose crafted from well-argued paragraphs. Feldman’s piece begins unbidden, as if it had been going on the whole time, and it proceeds with nary a caesura until a sudden reverberating pause in the final ten minutes of the work, signalling an entropic coda of some kind. The sudden cessation of movement is simply breathtaking, like suddenly glimpsing starlight from the middle of a dark thicket. The general lack of musical punctuation recalls the text of Beckett’s Neither, which Feldman would set as a kind of anti-opera for soprano and orchestra in 1977, and whose sixteen lines feature only three commas.

‘There is activity but no warmth’, wrote one review of a recording of For Samuel Beckett a few years back. It is music that just is, with a Zen-like detachment inversely proportional to the emotional and cognitive effect it has on listeners – or me, at least. Destroying your sense of your place in time is, at points, enormously anxiety inducing. After a while, though, it is strangely freeing, as you simply let the music run its course and try to tune into its subtle harmonic colours and intuit its minute variations. Structural margins are blurry, nearly invisible, like the delicate edges of Mark Rothko’s vast rectangles, whom Feldman would also celebrate in an enigmatic, prayer-like work from 1971.

It is music that both vexes and solicits intensely focused listening, encouraging a detached idleness (just let it work on you) as well as cognitive frustration (why can’t I find my way through this?). Beckett felt that failure was the essence of art. He reflects philosopher Maurice Blanchot’s idea of ‘désœuvrement’ – ‘worklessness’ or ‘unworking’ – a kind of static, blank void at the centre of the aesthetic. It was exemplified for Blanchot in Orpheus’s attempt to bring Eurydice back into the light from Hades, drawn to look at that which he can never apprehend and obliterating it thereby. Feldman’s work, which should be mounted more widely, draws its audience to reflect on the complexity and perversity of what it means to look at and listen to artworks, and the mysterious forms of attention entailed in doing so.