The most improbably exhilarating record I've ever heard was recorded 40 years ago, at a special late show in the Cologne Opera House, in front of a youthful capacity crowd. It's likely the only opera-related album I've ever listened to more than once, but that's fitting, since few of the 1,400 young Germans in attendance on January 24, 1975 were regulars, either. They'd come that night to hear something even rarer and less commercial: an hour-long improvisation on solo piano by a 29-year-old Pennsylvanian named Keith Jarrett.

Perhaps you think that 60 minutes of unbroken, off-the-cuff doodling sounds indulgent and esoteric, in which case you've never heard The Köln Concert, the double-LP of the show released later that year. Perhaps you think that an entirely improvised live jazz album by a single musician must have been, at best, a cult object, in which case it might surprise you to learn that it turned Jarrett into one of the least likely pop stars in history; to date, it has sold an estimated 3.5 million copies, placing it alongside Miles Davis's Kind of Blue as one of the most popular jazz records ever. By decade's end, Jarrett would be release a 10-LP (!!!!) live album and perform solo on Saturday Night Live. In the words of Guardian jazz critic John Fordham, "His concerts began to resemble religious rituals, attended by flocks of devotees for whom his music had a meditative, spiritual, and transformative power." The mid-'70s were a wild time.

When he arrived in Cologne, Jarrett was a young performer but a seasoned one, with nearly a decade of professional jazz-making already behind him. He'd played piano for saxophonist Charles Lloyd before joining Miles Davis's band in 1970 and switching over to keyboard. This was a particularly tumultuous moment for Davis—his music had become unprecedentedly dense, expansive, and rhythmic, with songs often stretching to nearly a half-hour and featuring multiple drummers and bassists. The two Miles records that included Jarrett—Live at the Fillmore and Live-Evil—are some of the most frenzied and aggressive jazz ever put to tape, full of long, minimally harmonic arrangements and feral soloing. This was jazz as Afro-futurist squall, a Jackson Pollock deconstruction of Duke Ellington's famed "jungle sound" from the 1920's. But Jarrett, a seeker type and a musical prodigy, needed more space for expression than that hurricane allowed.

He left the group in December 1971 and was soon approached by Manfred Eicher, a German national who had recently started his own imprint, ECM Records. Eicher lured Jarrett with the promise of absolute artistic freedom, and the pianist obliged with a studio recording, Facing You, made up of solo improvisations. The polar opposite of Davis's cacophony, this playing was marvelously clean, direct, and acoustic, as approachable as pop without any of the rock-audience pandering that marked many fusion groups of the time. The record was a small success, particularly among jazz fans, and Eicher decided to take Jarrett on the road.

Europe was in many ways a more friendly audience for jazz musicians than America at the time. While the number of Stateside jazz clubs shrank throughout the '60s, the music was brandished by younger Europeans as a revolutionary totem. Artists from throughout the continent, like Poland's Tomasz Stanko and Norway's Jan Garbarek, endowed jazz with new tonalities that strayed far from the blues, bop, or cool modal approaches developed in the U.S. But European audiences were also hungry for American performers, and Jarrett was a known quantity, having toured prodigiously overseas as a member of Lloyd's and Davis's bands. Eicher started him on a regular circuit of European markets whenever his schedule allowed, and Jarrett developed his fully improvised style in places like Bergamo, Bern, Geneva, and Molde. Most nights he would play two half-hour movements followed by a five-minute encore; a typical performance would glide between extended, almost gospel-like rhythmic passages and lyrical, balladic sections, often devolving into freer, atonal moments along the way.

Jarrett became a phenomenon, as much for the audacity of his method as for the strangeness of his stagecraft. He often resembled a gymnast more than a pianist—standing up, wildly contorting his arms, breathing heavily, and chanting along with his melodies. His concerts were feats of athletic as well as creative stamina, but there was a deep spiritual element to them as well, as Jarrett made clear in the liner notes for his first live ECM recording, the triple-LP set Solo Concerts: Bremen/Lausanne, released in 1973. Declaring himself to be on a distinctly untrendy "anti-electric crusade," Jarrett further explained himself:

I don't believe I can create, but that I can be a channel for the Creative. I do believe in the Creator, and so in reality this is his album through me to you, with as little in between as possible on this media-conscious earth.

This kind of vague religious psychobabble and pop-skepticism likely fits well within your conception of 1973, the heyday of Mother Earth News, Dr. Bronner's Magic Soaps, and the Back to the Land and communal-living movements. Within a few years, DownBeat would describe Jarrett's droning, meditative sections as "sonic mandalas," while Melody Maker would suggest that his music enforced a "hands clasped and kaftans on" vibe. But the very fact that his music was being covered in the pop-minded and jazz-averse Melody Maker at all was proof of how deeply aligned Jarrett was with other musicians of the time: He evinced and echoed the passionate drones of Ravi Shankar, the purposeful repetitions of James Brown, and the wildly ambitious structures of Soft Machine and Yes, not to mention the proud sonic primitivism of Neil Young.

Which is all to say, the world was ready for The Köln Concert, or at least more prepared for it than might be assumed 40 years on. Certainly the mood was right in the opera house itself, where Jarrett was booked as the fifth show in the so-called Jazz at Cologne series, organized by a teenaged aficionado named Vera Brandes. Selling tickets at only four German marks apiece, Brandes ensured a full house, almost all of the attendees around Jarrett's age. For his part, he took the stage looking "fresh from the musical Hair," as one onlooker recently told the BBC.

Jarrett was sleep-deprived and harried that night, and his mood wasn't helped by the fact that the opera house had supplied a relatively small, poorly tuned piano rather than the Bösendorfer grand that he requested. Even after an emergency tuning, the instrument supposedly sounded like a toy, with shrieking high notes and little projection in the low registers. On the record, having passed through two microphones, the piano has an almost otherworldly sound, like it's five stories high and made of glass. Jarrett plays it harder than he does on his other solo recordings, bashing the keys and keeping largely to the mid-range notes, perhaps out of frustration. "What happened with this piano was that I was forced to play in what was—at the time—a new way," he explained years later. "Somehow I felt I had to bring out whatever qualities this instrument had."

This is all backstory and context, but as an album, The Köln Concert melts context, vaporizes it: Purely as music, it exists outside time and space. It's a perfect product of the shaggy, stoner '70s, but it sounds completely modern right now and will remain so 40 years from now. Like everything ECM releases, it sounds somewhat clinical in a European fashion, but Jarrett's musical imagination is undeniably American, spanning funk, blues, and pop balladry. I agree with Geoff Dyer's assessment that "when Jarrett is at his best, snatches of all kinds of music flow through his work, but there is never any sense of strain, of a conscious effort to combine these disparate influences." This is as close as you'll ever come to actually hearing a genius think. The ideas build and mutate, and Jarrett is such a shockingly talented instrumentalist that there seems to be no distance between his brain and his fingers.

Jarrett has remained uncommonly prolific in the four decades since Köln, though his music has rarely bore any resemblance to it. He continued to play solo improvised concerts for decades, and in the early 1980s founded the Standards Trio with fellow Davis and Lloyd alumnus Jack DeJohnette on drums and Gary Peacock on bass; their body of work, largely drawn from the American songbook, is as respected as any contemporary jazz combo's, and they remain a reliable live draw. But Jarrett's contemporary compositions are rarely so genreless and accessible as his 1975 masterpiece, and his concerts have never regained that group-séance feel. In fact, his prickliness onstage—pausing to lecture audiences on the rudeness of coughing, for example—has become nearly as legendary as his still-inspired playing.

But what a marvelous, bizarre thing that an artist like this can become so popular, even for a moment, embraced by people, like my dad, who barely messed with jazz besides. I first discovered Köln in our basement, among Dad's old LPs, sandwiched among Ten Years After, Grin, and Mountain. I was a young teenager, intrigued by the spare album art and curious as to how Dad could like something so New-Agey. When I listen to it now, I get the same feeling I had the first time: I feel stronger, smarter, more inspired. It works when I'm sad, when I'm joyful, when I'm driving or falling asleep.

In David Foster Wallace's 1989 story "Girl With Curious Hair," the unnamed sociopathic narrator goes with his dirtbag friends to a solo Keith Jarrett concert in the early '80s. The friends drop acid, and one explains that the improvisation "smelled like old velvet in a trunk in an attic, or like vitamins, or medicine, or morning … [It] resembled weak sunlight through ice." That's true enough, but I prefer the brevity of the awful narrator, who's never heard Jarrett's music before and who, sober, declares with great enthusiasm that the show is "punkrock." The Köln Concert will remain ever so.


John Lingan has written for Slate, The New Republic, The Virginia Quarterly Review, and lots of other places. He lives in Maryland, and is on Twitter.

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