ROCK / The crowd goes bananas: Here we go again: Giles Smith met the members of the Velvet Underground and watched their first show for 25 years

At the end of the Velvet Underground's show in Edinburgh, after the encores ('Waiting for the Man' and 'Heroin'), the audience thunders its approval and the band, none of whom are wearing shades, gathers stage-centre. John Cale gives Lou Reed an awkward, one-armed hug. Sterling Morrison pats Maureen Tucker on the head. Everybody bows. They did it: an entire show without splitting up.

As a musical event, the Velvet Underground reunion is clearly a small slice of history, but as a piece of social engineering, it's a masterpiece. The last time that these four made music - part tuneful pop, part horrible racket - it was the late Sixties. They've been plagiarised for look and sound ever since. But Reed dumped Cale. Then Reed resigned, and Morrison didn't talk to him for years. The first show on Tuesday night was an entertainment, if hesitant and a little stiff at the joints. But perhaps it was somewhat eclipsed by the fact of the show. This is the comeback to end all comebacks.

At their hotel on the morning before their first concert for a quarter of a century, the Velvet Underground are available for interview - though not all at once. Cale and Reed can be seen separately, Tucker and Morrison together. Cale is mildy edgy and unsmiling. Reed, who has just read a less than favourable magazine article about himself, is on particularly nerve-splintering form. (In a low, menacing drawl and somehow grinding his teeth as he speaks, he opens the conversation with, 'I'm fed up with people being nice and then writing shit,' which could be interpreted as a form of warning shot.)

Tucker and Morrison, on the other hand, seem to come from an altogether different world - a world where people order pancakes, drink coffee and crack jokes with each other. ('Am I doing this interview with you, Mo? If not, clear off.' 'You having a problem this morning, dear?') When they use the word 'fun' - which has become the band's buzzword in the lead-up to their return - it seems to have a plausible ring to it. Almost.

In November last year, the group met in New York at the instigation of Polygram records, to discuss how a boxed CD of their music might be best compiled. According to Morrison, who recently completed a PhD, 'We hadn't had a band meeting to discuss business since the band split up.' They had lunch in the lobby at the Paramount Hotel and talked about playing, eventually deciding to have a practice session, to see how it felt. 'There was no way to predict what was going to happen,' says Morrison. 'Our practices even in the old days were somewhat peculiar. Sometimes we just sat around and talked and didn't play anything.'

But this time they played. 'We improvised,' says Cale. 'I got a bass riff and off we went, for several minutes. Then we tried some of the songs. Things written after I was . . . disengaged.' Evidently, it felt 'great' - 'fun', even. The band set aside three weeks for rehearsing in earnest and began to plot a tour.

'We immediately confronted the issue of playing in New York,' says Morrison. 'We decided it would be much easier to play nowhere at all. What about the West Coast? No thanks. Let's go to Europe where they like the records better and where we're more likely to have a good time. Our plan is just as limited as we represent it. The tour ends at the start of July. Then we go back to the States and obscurity and dissolution.'

Cale says the atmosphere during the rehearsal period was 'fairly subdued. Sterling was very up, but Maureen was the one who disciplined. She didn't say very much, but when she did it was very much cracking the whip. When it came down to what the ideas were, Maureen was the bastion of purity.'

Reed was working with a new toy, a rack-system enabling him to switch and combine the sounds coming from his guitar. 'It was built over seven months last year by a genius in London named Pete Cornish. It's the rack of doom. We call it Big Lou. I have a few pictures of it in my apartment. Some people have pictures of their girlfriends, I have a picture of my rack. I wouldn't want not to bring that to the Velvet Underground party.'

'We worked on keeping Lou's guitar quiet,' says Cale. 'When we went to rehearsal studio in London, we measured his amp, and he was turning out 12 watts of power. It felt like 2,000. In 'The Gift' (in which Cale reads a short story by Reed in the face of an instrumental barrage), it was physically difficult to finish the sentence with a guitar taking your head off.'

Reed says of the songs, 'They all have an essential heart which seems the same. It's just the way you approach it might be different, like the way you hang your hat. The time I did the songs with the group, I was in the songs, I had just written them, I was in the middle of it. Now I'm coming back to it - but it's not very hard for me to throw a switch and be in them.'

Sound technology has leapt on since the Velvet Underground last tortured amplifiers for feedback. The new opportunities for clarity seem to trouble Cale. 'The homogeneity of the sound of the band is really in jeopardy when you have the capacity for separation. I know that Lou applies it very assiduously to his own band. If that happens here, it could spell the death knell of what we really were about.'

But Reed says, 'Why would we stand there and try and sound like 1967? Do you think we should use cheap instruments, bad amplifiers, bring a bad sound company with us, make it as ratty as possible so people could say, 'Ah, listen to that'? They didn't have mixing boards back then - do you think we shouldn't mix it?'

'I don't think audiophile thinking suits this band very much,' Cale says. 'We're setting up our levels on stage so that we can hear each other. And that's a good discipline. But what you can't do when that's set up, is take off on your own into a vortex of loudness . . .'

Cale has other anxieties about how the show is going to look. 'If you give lighting guys just a little bit of leeway, they'll come back at you and try and re-order your set. The way they create atmospheres around you - I'm not even sure that the atmospheres are really what we want. We used to play in the dark. And I'm afraid the way we look now is a bit slick. I've seen bits from inside it that look very MTV. It's questionable whether that's really what we want or not.' But Reed is quite keen on the lights: 'We need to be able to see each other.' The show was designed by his wife, Sylvia.

In rehearsal, the band toyed with about 30 songs. Cale: 'The mundane aspect of it was, before you threw them out you had to learn them. And after you'd learned them, you had to play them well enough so you could decide whether you hated them or not.' In the end, a large quantity of the songs chose themselves. As Tucker (who is a mother of five now) says, 'If I had waited 25 years to see a band I was a lunatic about, I would be pissed off if they didn't play the old stuff.'

At Edinburgh, they played the old stuff - a sackful of it. The first voice you heard was Reed's ('One, two, three, four . . .') and the band plunged in to 'We're Gonna Have a Real Good Time Together', Tucker standing at the kit, Reed rocking his hips, Morrison standing stock still, Cale walking elegantly. The song sped by, but the volume kept low. It stayed that way, even when Cale picked up a viola and scraped his way into 'Venus in Furs'.

The crowd satisfied, fairly closely, a prediction of Tucker's: 'Two thirds of the audience will be young people to whom our music is new.' In the stalls, everybody stood from start to finish, but something - perhaps the lack of volume, perhaps the mistaken sense that this was some kind of rock pageant - prevented people from flinging themselves about. But then Tucker came to the front, wedged a finger in one ear and sang a frail and quavering version of 'Afterhours'. And after that the show seemed to find a rhythm. They played a clipped 'Sweet Jane', they played 'Some Kinda Love' and 'Rock and Roll'.

They also threw in a new song, called 'Mr Rain', which will be nice when it's finished. But when Cale sat at the piano and sang 'All Tomorrow's Parties', it satisfied his definition of the Velvet Underground when things are going well: 'Four simple elements combining to make something grand.'

See Gigs, opposite, for details

(Photograph omitted)