Ninety minutes of edge-of-the-seat drama, and a blistering starting eleven: not the Champions League final, but Pierre-Laurent Aimard at the Queen Elizabeth Hall in numbers I-XI of Karlheinz Stockhausen’s Klavierstücke. Dare I say we got something even more thrilling.

Pierre-Laurent Aimard © Marco Borggreve
Pierre-Laurent Aimard
© Marco Borggreve

Klavierstücke’s understated title (“Pieces for Piano”) belies music of unyielding intensity and atavistic power. The scale and transcendental inventiveness of this music means that it brooks comparison with only a handful of other great works for piano solo, which also create the impression of having invented music ex nihilo: Bach’s Art of Fugue, Beethoven’s Diabelli Variations, or, closer to Stockhausen himself, Messiaen’s Vingt Regards sur L’Enfant-Jésus.

This music, composed intermittently between 1952 and 1961, is nearly seventy years old, closer to The Rite of Spring in its time than we are to it. But as this Stockhausen season at the Southbank Centre has shown, music that is truly, madly new tends to radiate its originality only after a time-lag.

The work places huge demands on the audience. Special mention should go to the page turner, whose name I do not know, who must’ve been doing one of the hardest jobs in classical music in London that night, displaying grace and poise in extremis. It is music that demands unflinching alertness, asking audiences to dwell fully in its unique sonic logic.

Aimard’s chosen order for the eleven pieces – III, IV, II, I, V, VIII, VII, VI, XI, IX, X – held the first four pieces together as a kind of inverted miniature sonata, and staggered the longer pieces towards the end: VI lasts twenty-five minutes; IX is variable in length and aleatoric in its structure; and X is a twenty-minute tidal wave of virtuosity and sound. At its most expansive, this is the music of the particle accelerator, generating and annihilating musical particles in a single instant, whether melodic gesture, rhythmic cell, or shard of textural inventiveness. The unbending intensity of Aimard’s performance let these moments of musical renewal and dissolution unfurl continuously. In this respect Aimard performed an astonishing and unforgettable feat.

The earliest pieces of this cycle describe the pointillist sensibility of Webern and Messiaen, stringent and sometimes unyielding. Aimard pulled out their raw musicality, with breathtaking impressions of their timbral inventiveness: a whisper of flute, the bite of a string harmonic or the distant grumble of funerary trombones. The middle pieces displayed Stockhausen’s fascination with the piano’s harmonic resonances and overtones – a gift for Aimard, who explored their musical and textural possibilities with exceptional subtlety and control: in his hands they seared and set the teeth on edge, in more ghostly moments made hairs stand up or enfolded the audience in a glowing, somnambulant warmth.

The final forty minutes were magic. IX’s driving chords, heavy and subterranean, effortlessly relinquished their weight to climb into the thin air of the musical stratosphere, and XI’s improvisatory manoeuvres teemed with the seemingly limitless possibilities of Stockhausen’s sound-world. Aimard performed X, the last piece, with such commitment and physicality that I genuinely feared he might injure himself. Its music is literally and metaphorically bruising: huge forearm smashes and extreme glissandi that necessitate fingerless gloves. X is as deafening as the great piano works of Beethoven and Liszt, but also has passages of extreme quiet and abyssal, deep-space silences, heightened in intricate pedalling. Aimard’s virtuosity was unlimited and unfettered: I have rarely witnessed a musician give themselves over so wholly to one work in performance. I was reminded of the great, blistering monologues of Samuel Beckett and the fiercely primal choreography of Pina Bausch.

Aimard’s ovation was so huge that the concert could’ve stopped right there. But 1959’s Kontakte delivered more of this shamanic intensity. Aimard was joined by percussionist Dirk Rothbrust and Marco Stroppa, overseeing the electronics. Aimard, it turns out, plays the drums, his piano surrounded by a battery of gongs and crotales. He himself launched the weird, alien soundscape of the piece by drawing a metal beater over the huge tam-tam at the centre of the stage.

The “contacts” of the title describe the overlapping sonorities the piece is made of: pitched and unpitched sounds, natural and electronic, live and recorded. Its moments of contact also refer to the relationship between these triangulated elements: piano and percussion working together or drifting apart, sometimes challenging the electronic music that has reprocessed their timbres, sometimes floating away from it entirely.

Aimard and Rothbrust gave us moments of intense dialogue – bongos and xylophone parroting animated piano passagework – heightening the aliveness of their live music-making. Stroppa’s electronic interventions were always estranging and inventive. It was effortlessly theatrical, often disturbing, and never predictable. We floated out of the concert into the night on Stockhausen’s distant solar winds that close the piece out.