In a recent interview with America's Musician magazine, Larry Mullen sought to restore the balance: "Isn't it incredible that, when you reach a certain stage, everything (you do) suddenly becomes important? Everybody has been talking about the U2 phenomenon and not so much about the music."

It's a common complaint, after a sudden introduction to the fame game. Frequently the instinctive and self-protective reaction amongst musicians is to re-emphasise the mundane and deflate the myth. This is particularly so in the case of the drummer, who is U2's most tenacious guardian of practical musical values.

And yet Larry Mullen's comment does effectively set the agenda. In '87, U2 entered that twilight zone where the accessories of phenomenon tend to overwhelm the essentials of the music, in which all the fictive U2's of the millions' imaginations begin to swamp the core U2 the four in the hot seat hope they can still control.

As The Edge puts it: "Until 'The Joshua Tree', U2 were the biggest underground band in the world." This year, however, they became the New Kids on the celebrity block, the fresh faces of fame who weren't abusing their status as a short-cut to endorsing carbonated water and coca leaves, ideal icons to be elevated into the mass media mythic. This year they became c larger than life, perhaps also learning along the way that Christ's press agents, St. Paul and the four Gospellers, may just have been more powerful than the Messiah himself.

Conflict one, then - between the phenomenon and the music. But there is also a second tension between American and Irish perceptions of them. After all, U2 both live in and leave the land of their birth.

They export themselves (first and foremost) to a country where success is venerated and taken for granted. They live in a society still keyed to post-colonial failure and a supporting role in the celebrity stakes. Before U2, only Barry Fitzgerald went to Hollywood.

Thus, their success has amounted almost to a shock to the collective Irish cultural imagination. Usually, the odd swallow, a Stephen Roche, makes our summer. But U2's triumphs this year went far beyond even our most ambitious expectations. As a result, both in the responses to the Croke Park concerts and to Eamon Dunphy's biography, the non-music pundits (especially) seemed to be refitting U2 out for a contradictory array of causes, conveniently concentrating on the Bono Vox amplifier up front - but, equally conveniently, forgetting that there are also, drums, bass, guitar and vocals in the mix. By year's end, U2 were often publicly misconceived as being both impossibly larger (the social significance squad) and begrudgingly smaller (all the gossip that's fit to print) than they most adequately are. For Ireland, U2 represented a real problem of scale.

So, let's get back to basics: U2 are a rock band. Continue the basics: U2 might even concede they partially achieved their primacy because the competition, with the shadowy guerrilla exception of REM had collapsed. As now occurs with laughable regularity, U2 got tagged as this year's New Beatles - previous members of that exclusive club: The Police, The Bangles, The Raspberries and... urn... The Knack! - but unlike the Sixties, there were no counterparts like The Rolling Stones, Dylan, The Byrds and The Beach Boys to grapple for supremacy with them. In ' 87, as both Pink Floyd and The Grateful Dead betrayed rock's wrinkles and middle-aged flab, U2 were the only white and verifiably young rock group of equally verifiable substance about whom columnists could raze the Oregon forests, penning significant, generational essays.

But forget the rind, there's also a new seed. I fly to America with some inkling of new developments, of a concert film and a live album. What I haven't anticipated is a creative re-birth and a song-writing surge that together amounts to yet another new U2 being born.

These changes went latent in "The Joshua Tree" but suddenly I seem to be meeting the members of some born-again post-punk, Post-blues, Post-country, post-gospel, post-Everything Bar The Apocalypse band. Larry Mullen comes out of the closet as a country fan. Bono writes songs for B.B. King and Roy Orbison. They record demos in Sun Studios and adopt the alter ego of The Dalton Brothers. "Actually," says The Edge tellingly, "we've fallen in love with music again."

But this weekend, America may have other priorities. At Thanksgiving, America closes down for outside examination as planes and boats and trains bear prodigal sons and daughters home for their turkey, cranberry sauce, sweet potatoes and a binge of American football, making this interloping Irishman feel like a Hindu at Eastertime. And in Baton Rouge, the state capital of Louisiana, beside Robbie Robertson's "Crazy River", the vast inscrutable Mississippi, the sleeping South is sleepier still and the efficiency of - successively - my airline, hotel and local taxi-driver make Irish tourist ways and laws seem positively teutonic in comparison.

It doesn't seem the most immediately stimulating time and place to explore the love affair between U2 and America. Baton Rouge is a new city for the band. They've previously played New Orleans, a hundred miles downriver but as with the following Nashville/Murfreesboro' date, Baton Rouge has been tacked onto the end of the tour. Or, "the giddy part", in Paul McGuinness' cautionary words. U2 have twice traversed America, passed the peaks of New York and Los Angeles and are now in freefall, experiencing that combination of road-weariness and disorientation that induced the Seventies sport of hotel re-decoration.

To the concert, then, on the campus of the city's university, to find tour publicist Regine Moylett being pestered by a Texas freelance who claims he's writing an in-depth, socio-political feature for The Sun - a notable if naively original scheme to get free tickets. Inside, it's an ideal American auditorium, a purposebuilt basketball arena that seats 12,000 in the round in comfort and intimacy.

The audience is apparently classless, essentially costumeless. Away from the coasts, Americans don't practice the dedicated tribal segregation of the Brit, the only slight eccentricity amid the jeans and leisurewear being a discreet sprinkling of Madonna/Goth frills'n'lace, the most tangible signs of their veneration being a few tricolours and banners, even including one dyed "Bono For President".

Certainly U2 arrive to the sort of lung-busting tumult that elsewhere greets a presidential nomination yet, at times, the Baton Rouge crowd seem almost to be smothering the four in their circle of affection and Southern hospitality. Possibly too, they're partly representative of the more pop-orientated audience U2 have landed with "The Joshua Tree".

They don't always get their cues. Before "Sunday Bloody Sunday" Bono talks about how it's wrong "to bully small countries the size of Ireland- (grand cheer) "or Nicaragua" but the second example gets a more confused, muted response so he misses full impact.

It is a practised, enjoyable and sometimes playful set but one inevitably less headlong and incisively intense than their Irish summer performances, as if these veterans are playing within themselves - like a Liverpool 2-0 cakewalk at Oxford - which is more instructive for those telltale moments when consummation doesn't quite occur.

The new earthed roots-rock U2 doesn't always mesh with the old, skydiving approach, "Exit" segues into "Silver And Gold" as if the only common denominator is the Edge's clanging guitar. At times on "Exit" and on the quote from "Sympathy For The Devil" in "Bad" – "pleased to meet you, hope you guessed my name" - it seems as if Bono wants to temporarily escape those enveloping sunshine smiles. Even kindness can kill a band.

"The organisation is fraying at the edges. The real story of 1987 concerns five people first - but also Anne-Louise Kelly, Ossie Kilkenny and all those people who've committed so much time and energy to the band - just trying to stay head above water in a tidal wave of a year. As John Lennon wrote so well: 'Nobody told us, there'd be days like these'."

Next evening, on their free day in Nashville, Bono sits in a corner of the hotel dining-room, reflecting on the year's starcrossed activity, his pride mixed with some rueful tinctures, acknowledging that U2's relationship with their native country wasn't always comfortable.

"We had this idea in our heads that here we were, this Irish group in Ireland, and we thought we could literally back out of Ireland into the rest of the world with our armour up. And the idea that we would ever have to turn around and face a rearguard action from our own kind was something we hadn't quite planned on and literally took us aback."

He snatches a laugh. Bono knows well these are problems 99.99% of bands in Ireland, and the world, would sell their grannies into white slavery for. Nonetheless, he's irked by certain coverage of Eamon Dunphy's biography and criticisms of the band's Mother label by both Sinead O'Connor and the Dublin band Aslan.

He continues: "Like bands who attempt to help out, and maybe get it wrong, will actually get space by saying you're like any other record company. Or people you've met along the way all believe that their own version of U2 is what the world needs to hear."

For any sins of omission, he pleads disorganisation: "When those phone calls are ringing every day of the week twelve hours a day, it's a madhouse... U2 a corporation? It's much more like 5 Go Down To The Sea and can't swim. Ruthless bastards, no. Inept sometimes, yes. We made a lot of mistakes this year in the planning of our own tour and our own lives. Sometimes, our planning of other people's lives has been 10 on a list of 100 when it should have been first."

But he acknowledges the near inevitability of it all. "You become an icon and the iconoclasts of the world will take the piss and throw pot-shots at you. And if I were on the other side, maybe I'd have reacted the very same way."

Over-sensitive and regularly prone to gestures of overspontaneous generosity, Bono can cause overload when, as sometimes happens, he hasn't fully thought through how his promises can become flesh. Now he's stepping back from Mother.

One reason, though he still champions The Subterraneans, Hothouse Flowers and The Real Wild West, is a sense of disillusionment with imitative Irish music. But another is that "Larry and Adam are taking over Mother because they're people who find it very easy to say 'No' and if people get pissed off with them, they don't mind - whereas I get pissed off too."

He recounts Pete Townshend's advice: "He took me aside. About Mother, he said, you're making a big mistake. He said, with The Who, we went down many side-roads and back-roads and lost sight of Main Street. We set up this, that and the other. And often, he said, if you attempt to help people, they'll hate you for it in the end. And I said, no. No. But, he said, really they will. "And in 1987, in Ireland, I see that maybe rock'n'roll bands might be better off if Mother didn't exist."

His doubts may be the result of U2 ending up as the only game in town. Significantly Bono now speaks of being more comfortable with people like Christy Moore, Makem And Clancy, Ronnie Drew and Clannad than his near-contemporaries.

In '87, nobody's yet threatening to rival them, even as a medium-scale attraction. Besides Mother may have fulfilled its original purpose as a launch-pad, now that In Tua Nua, Cactus World News, Tuesday Blue and Hothouse Flowers have flown the nest. Without redefinition of its function, Mother could become a source of spoon-fed dependency far from any name of pride.

That's not much stimulus. Meanwhile outside is America. Exiles off main street, The Dalton Brothers enter its arms. There's nowhere else to go.

Bono must always be romantic. If, on "The Joshua Tree", U2 set their sights on American authoritarianism, now they're looking for stars in bars. Now Bono runs that voodoo down.

"I actually find it hard to go asleep over here, to blink in case I miss something. I find, for instance, the language very accessible. American writers, from Tennessee Williams through the Black and American Indian poets I'm reading, they seem to be 'sexier'. Sexuality and spirituality co-exist in American music, in a way they don't in Irish or British music.

"Music and words are falling off the buildings here. In the red-light districts. In the neon signs. In the down-town areas. Even in the jive, the names of' the roads."

He speaks of mysteries. Mightn't there be a public America that's fearful of them?

"Sure. That isn't an America I see a lot of - but generally, it's the other side that interests me anyway. The late-night bars. The fall of America interests me as much as the rise of America."

So, later that night, we check out Nashville's own neon blur. A small tour party including Bono, Ali and the Edge venture out. But it ain't so lyrical. We pass a club featuring Donna Mead, the well-known singing Northside shopping centre. Bono's pun, for it is his, must be sub-conscious. Because despite its association with the folksy values of country music, downtown Nashville is a gloomy monument to the entombing architecture of institutional America. Not unlike environment commentator Frank McDonald's vision of I fell, the centre is ringed by freeways and cluttered to suffocation by massive office blocks. The developers tore the country from Nashville's heart, long ago. They probably held a hoedown to announce their plans.

At night, most human life has fled. Typical is Tootsie's. Once this bar was Nashville in the rare oul' times, where the country stars regularly relaxed after-hours. But now, as we walk in, the signed photographs on the wall are starting to fade and curl. When the studios moved out of town, Tootsie's was condemned to be a back-water.

Now as two guitarists play Hank Williams for tips and we buy our Buds, our only company on lonely street is another party of tourists. A restless Bono prowls to the bar across the street but that joint ain't jumpin' either. Here, the only outlaw the Dalton Brothers meet is a lone panhandler begging for dimes as we leave. Another bar has more warmth and custom. A six-piece band slips easily between country, blue-eyed soul and rock'n'roll, the celebrity guests gag on free, sugary, sparkling wine and the guitarist sings the only folk song he knows: Van Morrison's magnificent and moody "Brown Eyed Girl".

But Bono and the Edge don't notice. Instead they're talking to a topless dancer from the next-door club. "She told me they only last six months," Bono relates. "Because the guys prefer them nervous and vulnerable. Once they look experienced, they're sacked." Turns out herself and her boyfriend claim they're Christians, only paying the rent, living out the small-change of American contradictions, in this concrete'n'western town.

Such distractions keep a band sane. Sometimes that social pan-handling finds a nugget of a song line. As The Edge later remarks, "You really have to look in this country to find out what's happening. When we first came here, America was like walking into an episode of Starsky And Hutch. Everybody would talk the same. I used to think TV America was exaggerated. It wasn't. Miami Vice goes on every day in every major American city. But once we were here two or three times, we were able to refine. We were like prospectors, coming here to find the gold. It wasn't easy. It was like finding the right people, radio stations and obscure record stores - and eventually finding the source of this thing."

The Edge talks of a renewed "love affair". Suddenly it seems U2 have become wide-eyed, though penetrating, fans of music they'd never reckoned with. Bono will speak of jazz and a recognition of horns - instruments which he used to deplore - with genuine enthusiasm. "I'm overpowered by the likes of Miles Davis. Suddenly at 27, listening to 'Bitches' Brew'. Discovering Gil Evans, seeing the sense jazz makes in cities like New York and Chicago. Seeing, for the first time, the poetry of folk music, of country. The release of gospel music."

What's potentially most intriguing is that U2 may be arriving at their enthusiasm from a position outside the institutionalized history of American popular music. Bono somewhat delightedly says: "Most people I've met who've turned me onto the blues are jealous because I'm getting into it for the first time. And they remember the time they got into it."

As the Edge astutely remarks: "Most average Americans don't really know about the heritage on their own doorstep. The music that's big in America is the Top 40 album, whatever's on radio. Our contemporaries and younger bands, have a very patchy understanding. So what we're finding, and I know it's bizarre, is that what we're now playing with is as new to our audience as it is to ourselves. We're not playing this music to people who know this stuff, although it's on their own doorstep, under their very noses.

He readily confesses he was the band's most reluctant convert. As a teenage guitarist, he'd reacted intensely against the older generation of Dublin players, with their squalling, posturing, hard rock vulgarization of the blues. "All that shit was like dirt. I'd purged myself of all that," he says. "So, coming back to that now was like visiting something laid and buried. It was like opening the coffin and I resisted a little. For instance, we disagreed vehemently about what songs should go on the album. If Bono had his way, 'The Joshua Tree' would have been more American and bluesy and I was trying to pull it back."

That compromise led to the later flood of new B-side tracks. Bono will argue that "the album is almost incomplete. 'With Or Without You' doesn't really make sense without 'Walk To The Water' or 'Luminous Times'. And 'Trip Through Your Wires' don't make that much sense without 'Sweetest Thing'."

Live, there hasn't always been such a neat resolution of the band's inner conflicts either. Last night in Baton Rouge, Bono admits "was a bad show. Not so much the band as myself. I completely lost myself. Being on a stage for me doesn't get any easier. Even in the Middle of 'Pride', the oddest thoughts come across me. I just want to pack up and go home.

"We're a snake who hasn't fully shed its skin," he believes, accepting that the creative U2 of '87 is co-existing uneasily with the U2 the fans want to hear. "That preys on me a lot. I don't know how to sing 'New Year's Day' now."

He looks up and laughs: "Now you're talking. All the other stuff, they aren't problems. This is the problem and what a problem!"

What a problem indeed!

Next night the soundcheck is almost as instructive as the concert. U2 chisel away at their new material and I hear their real aural testimony. Most songs are unfamiliar but "When Love Comes To Town", Bono's song for BB King, has put on musical muscle as well as two additional verses taking it far beyond its original lyrical simplicities since I heard its skeleton on an acoustic last spring.

It's neither a self-conscious pastiche nor a profane HM holler, U2 managing to enforce their own personality on the music, refusing to be drowned in the blues. Probably surprised, the local Southern staff give them the compliment of their applause.

Then veteran Irish guitarist and sometime Nashville resident, Philip Donnelly arrives to pick. The Daltons mutate into the (sm)Allman Bros, as The Edge forgets his teenage reluctance to copy an older generation of Irish players. The song itself reflects his observation: "I'm writing songs I can't describe. Some of them are blues, some of them are country, some of them are folky like the Byrds."

The show is also better. In Murfreesboro', the audience is more boisterous, less prone to shower U2 with amorphous affection than in Baton Rouge. Consequently, Bono has a more confident sense of what he's looking for.

Devils and angels interchange as the preacher takes his tale through a sequence of the killing hands of love and "Exit", Manson's favourite, "Helter Skelter", Lennon's plea for "Help" and a version of "Bad" which yet again includes "pleased to meet you, hope you guess my name" from "Sympathy For The Devil", with only a brief verse from "Silver And Gold". The persona isn't quite finished or even fully understood yet but you do recognise work in progress.

For U2 are no longer the wide-eyed Irish idealists of yore. By their profession, world citizens, they're finally admitting the deceptive imprecision of adult motivations, recognising now that their own experiences can't be adequately expressed in the primary colour of old. Comment on "The Joshua Tree" often centred on it, critique of public political morality but my hunch is that U2 are now really facing into the slippery choices of private morality, pulled through the paradoxes of a door marked "Exit".

The public mask can protect their private searching. Next year, a live record will accompany their concert film but they also want this double album to float off new material, a strategy that will allow them to both experiment and guide their audience.

Back in that Nashville hotel, Bono summed up the real deal: "If we can't play the old songs, then write new songs. It's our only way of surviving and getting through the tour. I actually don't care if people don't like it, though how many songs will be put on this album is not decided... you may not like it, U2 fans may not like it - but we need it."

BAND ON THE RUN

December 1987