Radiohead is a significant band at a bad time for significant bands. Radiohead took its name from a song by Talking Heads, which says something about Radiohead's aspirations, and something too about how self-conscious and historically freighted any aspiring band cannot help being now. Radiohead is making music at a moment when the epoch of bands would seem to be coming to a close, a moment when what is novel in popular music is being made not by groups of young men playing guitars and writing and singing their own songs but rather by individual D.J.'s and one- or two-person production teams using turntables and computers and assorted electronic gadgets. It's a moment that has the feel of a mainstream-music paradigm shift -- away from pop-rock and toward hip-hop, dance music and what gets called electronica. It's a moment nearly 40 years removed from the last big paradigm shift, secured by the advent of the first significant band, the Beatles, whom the members of Radiohead seem to talk about all the time.

Radiohead is a band that is dealing with the sea change in popular music in ways wholly unlike Limp Bizkit and the other "rap metal" bands whose albums have dominated the Billboard charts for the last two years -- bands that have taken the worst aspects of hip-hop (misogynist rap lyrics and monotonous beats) and fused them with heavy-metal white-guy bathos. Radiohead is a quintet whose members first met 15 years ago at the Abingdon School in Oxfordshire, England. They are not angry or wildly disaffected but serious, inward-turned and uneasy, in particular Thom Yorke, the band's lead singer. Yorke possesses one of the finest voices ever to grace a pop recording -- it circles operatically on its way to a lustrous falsetto, and it is what ultimately makes a Radiohead song a Radiohead song. Yorke is also the band's chief songwriter and driving force, or as he has put it: "We operate like the U.N. I'm America." Yorke would not speak to me for some time when I joined the band on the road for several days last month in Copenhagen, and he also chooses not to speak to his fellow band members from time to time, which tends to make them even more uneasy. ("Thom can be rather . . . hard on people," is how Nigel Godrich, the precocious young producer who works with Radiohead, put it, choosing his words carefully, so as not to make things harder for himself, I did not doubt.)

Three years ago, Radiohead confronted the looming end of album-based, guitar-saturated, lyric-dense rock by counterintuitively releasing "OK Computer," a 70's-redolent concept album stuffed with grandly contoured melodies, rigorous guitar patternings, odd time signatures, melancholy minor chords and atonal changes and weighty dystopian lyrics summoning a world of technological disasters, hypercapitalist conformity and things moving so fast that there was no longer time to do things like listen to painstakingly wrought, crepuscularly beautiful concept albums like "OK Computer." (If Don DeLillo's "Underworld" were a rock album, it would sound like "OK Computer.") The kind of aging white men who edit music journals and write rock criticism and still listen to albums under headphones (and many times over again) hailed "OK Computer" as a masterpiece, and a lot of other people loved it, too: it was nominated for the Album of the Year Grammy and has sold, at last count, 4.7 million copies worldwide. At one of the shows I saw the band play, it seemed half the mesmerized crowd (hipster student types, mostly) were singing along to the strangest song on the album, "Paranoid Android" -- a song that begins with the lyric "Please could you stop the noise I'm trying to get some rest/from all the unborn-chicken voices in my head," and climaxes six minutes later with a brooding Russianate chorale.

Radiohead is releasing a new album this week, its fourth. And in the music industry, which, in the wake of the success of "OK Computer," has been scrambling to sign Radiohead-esque bands (Travis, Coldplay, Muse and others), the new album has created that amorphous though tinglingly palpable sense of anticipation no album by a band has generated in years. (Playing no small role in this has been Radiohead's aggressively passive rollout strategy: no advanced single for radio and no video, though MTV is showing brief video "blips" provided by Radiohead that feature sound bites from the album.) Titled "Kid A," the new album is not a concept album, but it is, like its predecessor, one for the headphones.

"Kid A" has one genuine rock song, "Optimistic"; it's ja#nglingly reminiscent of R.E.M., a band whose music and artfully considered way of going about being pop musicians had a considerable influence on Radiohead early on. As for the other nine songs, many of them don't have verse-chorus structures, most of them blur at their edges beneath synthesizer- and radio-generated atmospherics and nearly all of them have lamentatory or incantatory or imperative lyrics built of fragments that might have been pulled from Tristan Tzara's hat. It is not "difficult" music, though, as searching as much of it is, mainly because the sonic textures Radiohead has worked up for the songs are so evocative and absorbing. Sounds from the past (a churchy harmonium, a bowed double bass, a florid, cascading harp) surge and fade amid burbling electro-beats, taped and looped vocals and computer-manipulated guitar and keyboard riffs: it's an aural palimpsest, its delights surfacing slowly, and concentrated in the rubs and the musically shaped spaces. For example, on the album's title track, the name for which was lifted from a software program of children's voices, a ravishing sound sculpture is constructed from an Old World music-box motif; a bit of jazzy drumming taped, cut and pasted; a Gramophone-era vocal melody stretched and garbled by a vocoder; and a watery foundation established by an Ondes Martinot, the protosynthesizer used by the French composer Olivier Messiaen, who is much admired by Radiohead's lead guitarist and keyboard experimenter, Jonny Greenwood.

Jonny's older brother, Colin, is Radiohead's bass player and, even in a band that unwinds back at the hotel by drinking a glass or two of wine and worrying about the consolidation of the British publishing industry, he stands out as the most intellectually minded member of the group. (He read English at Cambridge.) When I asked him one morning last month, while we sat and chatted in the gardens of Copenhagen's Rosenborg Castle, how "Kid A" had come about, he thought for a moment, cited a Leonard Bernstein dictum that all music-making is about ambiguity and deletion, mentioned matter-of-factly that during the "Kid A" sessions there had been moments when the band seemed on the verge of breaking up, then finally said: "The whole thing, really, comes down to finding a new sound. You think about the Beatles, they sort of came up with a new approach every album -- they listened to all this stuff then brought it to bear on their work. And that's how we work, too. But of course they were at the beginning, inventing how it could be done." He paused, and then he said, "We are people who have worked together for 15 years, a rare thing -- especially for men, when you think about it -and it's getting harder not only for us, but it would seem for music itself, to do something new."

The surprisingly strong sales of "OK Computer" may have been driven to some small degree by the overwhelming critical embrace of the album, but are more likely owed to the labors of the band itself, which spent a year and a half on three continents touring in support of the album. It is the way a band has always become big, and it is a terrible grind. Of course, only a band with considerable ambition would ever find itself out on the road that way. But Thom Yorke doesn't like the word "ambition."

"We used to be more ambitious," he said when I brought the topic up. "And what does that mean, anyway, ambition?"

I shifted a bit: hadn't the fame and fortune that resulted from the saturation touring of "OK Computer" brought Radiohead a whole new level of freedom and control?

"You can say we've earned the privilege to do things our way," he replied, "and I would say to you" -- and he did say it, and you can imagine.

Then he laughed a little and seemed slightly embarrassed. Yorke comes across as someone who has had to work up a certain hauteur to get what he wants aesthetically and also to insulate that art-minded aspect of him from all that encompasses the Biz. But there is also a boyish sweetness to him, and that English decency Orwell put such stock in, and that goes too for the other band members -- they hold doors and ask after the health and spirits of roadies and sign autographs in the cool drizzle outside their hotel as if they liked nothing more and apologize for everything. "Sorry," Yorke said to me. Then he thought for a moment before going on to say: "We knew a lot about bands, you know, about the endless touring and things you need to do to be able to be a big band at the end of all that. But by the end, those last months on the 'OK Computer' tour -- it was just totally wrong.

"You know," he continued, "we always had this idea that the good thing about being in a band was people clicking, keeping one another's interest going -- all the stuff you can't do in a bedroom by yourself. And here I was spending days thinking: The hell with this band. It was awful."

Yorke, who is 31, which is roughly the median age of a Radiohead member, was seated on a sofa and sipping white wine in the band's dressing room following one of the concerts last month in Copenhagen, an early stop on a brief European tour nothing like the one to promote "OK Computer." Because Radiohead can stand neither the acoustics nor the atmosphere of big arenas, each concert was being staged in a huge, custom-built tent carefully raised in a big city park. This required a crew of dozens not only to hoist and lower the indigo-colored tent but to work the custom sound and lighting systems that were fitted beneath them, and this crew, in turn, as well as the band and its crew -- managers, the "guitar tech," and so on -- were fed through the day by a catering team that also found time to shop locally each morning for an elaborate, multicourse preconcert dinner each night. Mornings and early afternoons were mostly free for band members to read, exercise, stroll around. Late in the afternoon they assembled under the tent for a brief sound check. Radiohead went on stage on the early side by rock standards, around 8:30, following an opening band (in Copenhagen, it was an arty Icelandic group called Sigur Ros), and were done by 11. "Thom just didn't want be working all the time anymore," Colin Greenwood said. "People still cling to this idea that bands don't work hard -- maybe they can't acknowledge it, since we are part of their leisure -- but it is hard."

Radiohead's two Copenhagen shows were workouts -- spirited, exacting and at times wondrous, as when, say, Jonny Greenwood "played" a transistor radio like a Stratocaster on one new song, or, when he and the band's other guitar player, Ed O'Brien, during another new one, knelt over sampling machines, capturing Thom Yorke's voice and strange electric-piano chord changes and sending them droning and echoing over the crowd like otherworldly plainsong. "It's set up as an experiment in a way, that song," Yorke said later. "I like that it cannot ever be the same any night by design. I get bored. I'm bored with the rock thing. Aren't you?"

One morning last month I drove through Abingdon, a picturesque market town, and then past the Abingdon School, with its brick-red Victorian buildings and beveled hedgerows and schoolboys in their blazers and ties, gathered on a wide stretch of lawn. Showing me around was Chris Hufford, a partner in Radiohead's longtime management team, Courtyard Management, and as he talked of how his son had decided against attending Abingdon -- Hufford and his associates have their offices in the nearby village of Sutton Courtenay -- I couldn't take my eyes off those public-school boys, baffled as to how the members of arguably the most significant band of this moment could have been among them not so many years before. At the Abingdon School, Colin Greenwood studied classical guitar, Selway studied percussion, Yorke wrote incidental music for a production of "A Midsummer Night's Dream" and Jonny Greenwood manned a viola chair in a local youth orchestra. What would become Radiohead more or less came together, at Yorke's instigation, in a school band room.

The success of Radiohead has brought with it the publication of no fewer than three quicky biographies of the band, and in each, the impetus for the band's formation, and, for that matter, the darkish modalities of its lyrics and music, are traced to Yorke's childhood, and a series of painful operations on his lazy left eye that not only failed to correct the condition but also damaged his vision and left his eyelid drooping slightly, for which he was ceaselessly ridiculed by other boys ("Salamander," he was called at Abingdon). Ultimately, though, Radiohead's roots are not that much different from those of the countless bands before them: they liked hanging out together, clique-style, shared a passion for particular recordings -- especially those of American groups like R.E.M. and the Boston-based college rockers the Pixies -- and thought playing music would be a great means of cementing their bond and a way to make use of it.

"The really weird thing is how serious I was about it," Ed O'Brien recalled one afternoon in Copenhagen.

"We all were," Jonny Greenwood quickly amended.

The three of us were having a cup of coffee at a bar near their Copenhagen hotel before they headed to the tent for a sound check.

Greenwood: "I went off to college, and it was for me, like, O.K., I hope this week isn't too rough, because I have to get back home for band practice this weekend. I mean, the band's been what I do -- been my life -- since I was 13."

O'Brien: "At Abingdon we'd rehearse, tape the rehearsal, listen to the tape of the rehearsal, rehearse some more. . . . "

Greenwood: "Yeah, we'd hardly ever play for anybody."

O'Brien: "Nobody liked us, except us."

Greenwood: "That's true."

O'Brien: "I'd play tapes of us for people when I went off to college -- I mean, the band was my raison d'tre -- and they'd give me that look that said: Keep studying."

Greenwood: "We were so serious."

O'Brien: "We'd sit together in a pub or something in Abingdon, which can be an incredibly boring place to be at that age -- maybe we're 16 or 17- and we'd lay out the plan of what we were going to do."

Greenwood: "I mean, when you really think about it -- "

O'Brien: "Uh-oh. I feel a Charlie Watts-ism coming here -- "

Greenwood: "Actually, I think we just wanted to make a record."

O'Brien: "More than that."

While Thom Yorke was at Exeter University in the late 1980's, where he studied art and literature, he wrote a song called "Creep." It's about a drunken guy, troubled by his self-image, for whom the sight of a young beauty brings on a crisis of confidence, and worse. Late in the summer of 1992, when Radiohead was in a studio to work on a single, it got recorded, almost as an afterthought, and the producers applauded. A four-song EP, their first recording after signing a deal with Britain's Parlophone label, which is part of the globe-spanning EMI Group, had been released at the end of 1991 in Britain, and gone nowhere. "Creep" pretty much went nowhere in Britain, too.

But the story of "Creep" does not end there. A music director at a San Francisco college station found the single in a Berkeley record shop's import rack and added it to his station's playlist. Within weeks it was an underground rage up and down the California coast. "Creep" was included on Radiohead's first album, "Pablo Honey," released in February 1993, and "Creep" drove it into the charts. A new, bowdlerized radio-edit version of "Creep" was produced for American modern rock stations, excising the emotive use of an obscenity, and the single went into deep rotation. By the end of the summer of 1993, "Creep" was a national alt-rock smash -- the next new slacker anthem, following Nirvana's "Smells Like Teen Spirit" and Beck's "Loser."

Radiohead toured America, and everywhere kids in flannel shirts screamed for "Creep." But often they would leave once the band played the song. And then a follow-up single went nowhere. And by the end of 1993, Radiohead was being written off.

Kids still yell for "Creep" at Radiohead concerts, which is an indication of how important a hit single can be in building a fan base. Radiohead won't play "Creep" anymore, and when I brought it up with Yorke, he lit into American radio, and how modern-rock D.J.'s tormented him with questions as to whether the "Creep" was him, and what had his parents or somebody done to him, did he think, to make him turn out this way: the pop-analysis inquiries of the grunge era. "You can't imagine how horrible that was," he told me. "And the thing about being a one-hit wonder: you know, you do come to believe it. You saw you don't but you do. It messed me up good and proper."

Kid A" came together not far from Abingdon, in a gathering of old stone barns that the band has converted into Radiohead Central, with recording studios, workstations, meeting areas and bedrooms. "Kid A" did not come together easily, however. In making the previous albums, it worked like this: Yorke would have some songs roughed out, and these would be added to songs left over from previous sessions, and the band would gather and rehearse them, each member going off into his corner for a day or two and working up his riff for a song or, perhaps, an entire idea for an arrangement. There would also be time during these rehearsals for listening to recordings each of the members happened to be intrigued by then.

"It's like you hear something and you say to the others, Let's aim for that -- that sound," Jonny Greenwood explained. "And then you might aim for that, knowing your style and limitations will keep you from ever getting there -- John Lennon said this -- but they will, as a result of where you've aimed, maybe get you somewhere new and great." (Greenwood mentioned that his obsession with Miles Davis's "Bitches Brew" had set the tone when they were working on "OK Computer." )

O'Brien had convinced himself, even before work began on the new album, that Radiohead should do a sort of back-to-roots guitar record, closer in feel to the band's second album, "The Bends." However, when he and the other band members gathered to rehearse and begin recording in a Paris studio in January of last year -- the new Oxfordshire complex was still under construction -- they learned that that was the last thing Yorke had in mind. He just didn't think guitar bands were "relevant" anymore, he told the other band members. He was interested most in new, more contemplative forms of hip-hop, like that produced by San Francisco's DJ Shadow; and Yorke had taken with him to Paris recordings from the early 90's by Autechre and the Aphex Twin, weavers of rave-scene chill-out sound tapestries. The other band members didn't get it.

"It was rather incredible to see," Nigel Godrich, who went to Paris with the band, recalled one evening a few weeks ago, sitting behind a control board at a studio in St. John's Wood. "I mean, Radiohead is a remarkable guitar band. But what Thom wanted now was a sound that doesn't tend to get made by bands."

The band left Paris having gotten nowhere and reassembled in Copenhagen a few weeks later. It got worse. The new songs Yorke had, dozens of them, were mostly sketches. Godrich recalls Yorke not talking much to anyone. O'Brien found the two weeks there "horrendous." In April, the group tried it again, in an empty mansion in Gloucestershire. There were tense meetings. What basically got decided was that the band would not split up. Phil Selway, Radiohead's soft-spoken drummer, told me : "I think what was happening back then was that for the first time we didn't have anything to push against as a group, and so we pushed against each other."

Not until early this year, with Radiohead regrouped in the new studios, did Yorke's idea for the album begin to sink in with everybody else. The band members became more comfortable with setting aside their instruments; at one point last winter they actually split into two groups in two different rooms, one of them charged with making and recording noises and musical snippets without using guitars or drums, the other with reworking this material technologically with studio gizmos and computers. The understanding grew that there would be tracks on which one or more of them would not appear. In a sense, the very notion of being a band member was evolving: what would count most now were taste and ideas. "We were working more like producers than musicians," Selway says.

By spring's end, they had enough material for two albums. That freed up time for another round of anguishing meetings about what tracks should make it onto the album, and in which sequence they should be arranged. "Nigel says working with us was like working with five method actors," Colin Greenwood says. Then, talking about the album itself, he went on to say, "I think we managed somehow to bend the machines to our will -- that's what we did together, as a band. We approached them our way, navely, without reading all those instruction manuals -- we don't have the patience for that. It's as if in this way we created a kind of false sense of the nostalgia some people get by using older synthesizers from the 70's and 80's."

Strangely, this does come through: Radiohead used up-to-the-minute methods to make a kind of artifact of the future's past- a work that weirdly harks back to right now and the looming exhaustion of the band paradigm.

Defying record-industry conventional wisdom, the band's current European tour will be all but over before the album's release, and there will be no American tour at all. Radiohead will appear on "Saturday Night Live" on Oct. 14, and play one concert at the Greek Theater in Los Angeles later in the month. The only radio show the band will visit is "Morning Becomes Eclectic," the art-pop drive-time show on the Santa Monica public-station KCRW. Radiohead's renunciation of the standard album-release strategy is talked about by industry people as the most understatedly ingenious publicity ploy since the Beatles' cover for the "white album."

Tony Wadsworth, president and C.E.O. of EMI, caught himself when he began to tell me recently about how commercially savvy the band is. But he did venture: "These five guys are at a point where they are not going to do a thing they don't want to do -- they're not going to be traveling salesmen. They want to find other ways of doing what has to be done to get their records into as many hands as possible."

The members of Radiohead talk about releasing more music from their recent sessions as early as next spring, either in album form, as an EP or online. They have also begun to discuss taking their tent tour to the United States next year. For the moment, they are not talking about not being Radiohead. "I think it will be our personal lives someday that get us drifting away from each other, not aesthetic disagreements," Colin Greenwood said. "I think we'll know the moment when it really comes, as opposed to all the moments when it almost really comes," said Ed O'Brien. Thom Yorke said: "I think we will exhaust all the ideas the band has. And then we'll exhaust the band."