The hall is large, a long rectangle, with high ceilings and a parquet floor of light wood. In the middle, four grand pianos wait, pointing at each other in a loose star of polished wood, innards of dull gold and the spotless black and white stripes of the keyboards. On one side is a conductor’s podium and, next to it, a laptop on a pedestal. Folding chairs are ranged around the pianos, though not on the sides where the pianos are close to the wall. There are also some chairs in the middle of the ‘star’, where the prows of the pianos point to each other, and these are already occupied. Next to each keyboard is a computer screen, black, with large timing numbers in white, frozen for now at 00:00. People enter and there is the buzz-bustle of an audience settling itself. By the time our group comes in, the chairs are all occupied and we quickly find ourselves space on the floor, against the wall, equidistant from two of the four pianos. We won’t be able to see two of the pianos, but no matter, we’ve done well, because, soon, the floor is quite crowded too.

Despite the classical pomp implied by the four grands, people are casually dressed, there are a few children, and there is not a suit or evening gown in sight. It’s clearly not going to be that kind of a performance. Four people, two men and two women get up from the chairs in the centre and move out to the piano stools. ‘Our’ two pianists (we can’t see the other two), calmly arrange their scores, flex their fingers, wrists and arms, adjust the stools under them. The conductor comes around for a last-minute check and whispered exchange before taking his place at the podium. After a while he makes eye-contact with each player in turn. Then, looking straight ahead, he brings down his arm in a chopping gesture. As the white time-numbers start to flicker on the screens, the wave crashes into the high ceiling, bounces off the walls, from the floor, and engulfs us.

Julius Eastman was an African-American musician and composer who came to notice in New York around 1966, worked with several avant-garde artists and musicians, notably among them Meredith Monk, composed his great pieces between the late 60s and early 80s and then died, broke and obscure, at the early age of 50, in 1990. His obituary only appeared six months after his death.

Nothing in the brochure for the concert — or indeed on Wikipedia — prepares one for the experience. Nothing in black American music — which, till now, I thought I knew well — sits next to this comfortably. Yet the river of sound that Eastman creates breaks the banks and pulls in all of it — slave-chants, spirituals, all of jazz, blues, motown, pop, funk, rock — and makes it pulsate and weave in with everything of Western classical music from Johann Bach to Karlheinz Stockhausen, Philip Glass and Steve Reich. All of it and yet, somehow, none of it. Eastman’s compositions, many of them, are available for listening on YouTube but I was grateful that I didn’t hear any before this live performance. We attended — witnessed — heard — saw — viscerally felt — the language tumbles wrongly from my keyboard, over-wrought, ludicrously inadequate, trying to elbow into the universe created by those other four keyboards, their cosmos of sound expanding, both dirty and clean, while the word-galaxies collapse into the gravitational pull of inarticulacy.

During one of the breaks between the three pieces played that night, I find myself sharing a cigarette-moment with a couple who are local residents of Basel, a performer who uses music in her work, and her husband, who is also a musician (and a union leader, as I later find out). We are all at varying corners of our fifties. All three of us are properly jaded, cynical about the new, deeply marinaded in the old surprises of great musical memories; we have all heard a lot of music performances in our time, and of all sorts. Yet it takes us no time to agree that this is one of the most transforming evenings of lives.

“But how will you write about this?” The man asks me. I tell him I have no idea. “Perhaps, you can only describe what happens to you.” He says. “You cannot describe this music, yes?” No — yes, I can try — and then again, no.

The three pieces performed that night are Evil Nigger, Gay Guerrilla and the longest of them, Crazy Nigger. All three were composed by Eastman around 1979-80, but it seems it’s only recently that the world of modern Western music has begun to pay attention to his work. Across the evening I’m immersed in the music, four different ships carrying me in four different directions and yet, repeatedly, flinging me on to some one same shore, though a different one each time.

In the audience, the older listeners sit stiffly straight in their chairs, their eyes closed in concentration. The people sitting on the floor relax, drop their shoulders, drop their heads into their arms, and then many of them stretch out, some of them right under the pianos. So unimaginably pleasurable is the mixture of grandeur and intimacy that the kids don’t know what to do with themselves; some wander, one little guy has his semi-asleep back massaged by his mother, another child chokes on a pretzel and is whipped off with speed, the mother’s high heels clacking through the Niagara wash. Girlfriend-boyfriend types entwine denim-legs, quite unselfconsciously, as if they were at a fireside in the woods. Potential lovers avoid touching closely aligned body points — perhaps — in case — the separate ecstasies they are keeping in check flood uncontrollably into unscheduled contact. A lot of people have their heads buried into the cage of their arms and knees, while many are looking up at the ceiling with glazed eyes or through shut eyelids. What thrills me is that this is not the swaying, jumping, informality of a rock show or a world-music gig, nor is it the formally philharmonicized ecstacy of a suited-booted Western classical concert, the closest it comes is to an Indian classical performance, but it is nothing like that either. We, people, clearly don’t know what to do with this music, yet the music knows exactly what to do with us.

Crazy Nigger, the final piece, begins with a desperately high morse code of loss transmitting between two pianos, which is then joined by the other two. Around 25.40 on the screen, there seems to be a santoor coming out of somewhere, then traces of Keith Jarrett at Cologne, though towering way over that cathedral, then, unmistakably, Tibetan prayer bells, while somewhere, far away, a stationary, old-style, US 212 area-code phone keeps ringing, goes off and rings again, clearly a serious emergency. All of it is piano and only piano, there are no other instruments participating, though sometimes, if you close your eyes, that becomes impossible to believe.

The information about Julius Eastman’s life says he became homeless and lived rough in the run-down area around Tompkins Square Park in south Manhattan. This happened in the early 80s, which is exactly when I lived right next to Tompkins Square. Walking home from the concert, remembering the last act, where some of the audience, the kids and grown ups join in, hitting the keyboards in a joyful cacophony of noise, I keep trying to remember the pariah Avenues A, B, C and D and some 40-year-old black hobo I might have seen huddling on a park-bench in winter. I come up with nothing. I remember being close to misery during that time and wondering as a 20-year-old how great art could possibly come, despite an empty stomach and the cruel world ignoring you. I still don’t know the answer, but after this evening, I do know, yet again, that come it does, when the evil, gay, crazy, transgressive robber in you yanks it down from wherever.