ONE: Friday 22nd June

Funny how we always drive into the Glastonbury festival via Pylle Village Hall, a little stone building cutely located at the side of a Somerset back road. I never give Pylle Village Hall another thought until the next time we play Glastonbury and there it is again, and I say to Steve or Richard: 'Look there's that funny village hall building again". "Oh yes, so it is" remarks Richard or Steve. And on we drive. I suppose this exchange is repeated in dozens of band vans or busses at every Glastonbury Festival. I wonder how the building feels about impinging minutely on many consciousnesses once every two or three years and then being forgotten till the next time.

After Pylle village Hall fades again from our minds we are into the relay of security check points as we trundle down the back lanes into the festival itself. All the security people are volunteers, and cheerful. And they have a very clever technique. None of them ever gives us directions for all the way we want to go, only to the next checkpoint. This is how they keep control of the incoming traffic. Very cunning.

It has rained and there is mud. All the band members have brought wellies except the irrepressibly cheerful and contrary Steve Wickham, who is still blithely proclaiming that he won't need any, even as we roll into the festival proper and see the muddy ocean all around us. Steve receives much roasting from the rest of us for his intransigence, but luckily our roadcrew have quietly procured a pair of green wellies for him (customised with black polka-dots with a magic marker pen).

I always enjoy the drive through the festival to the backstage area; our first opportunity to absorb the atmosphere and seriously connect with the spirit of the event. As we did in 1986, we open the side door of the van and shout and joke with festival-goers as we drive past them. Despite the mud everyone is in good spirits. We spot some great hats. My favourite is a round chinese-style reddish brown creation with a long thin spire rising from the top, sported by several people - must be one of this year's hit festival fashions.

Many people are dressed in fabulous, colourful outfits and probably the most spectacular sight on the way in is a wonderfully painted mermaid girl (in shades of blue with full fishtail) on the shoulders of a stocky blue man with a splendid gargoyle headmask. "I didn't know Van was playing this year" remarks one wag in our vehicle, who shall remain nameless.

We're playing three shows at this year's festival - one each day - and this evening we perform on the Avalon Stage. Never been at this one before, and it's in an area of the festival towards the Green/Healing/Earth areas, descendants of the original 1970s Glastonbury Fayre spirit, close to the Tipi Field and the Field of Lost Vagueness. The stage itself is under a bright blue and red striped tent, and behind it, in the backstage enclosure, we meet up with our roadcrew, all be-wellied and good humoured.

We've arrived purposefully early so that we can all head out into the festival and get the feel of it. But the first thing I want to do is stand on the stage and get the range of the performance space. Fortunately no one is playing when we arrive, so I step up the ramp and hang out for a few moments at the sides of the stage, unseen by the audience who are waiting for the next act, and get a sense of what it will be like to walk out in five hours time, with the crowd yelling and the lights blinding. When I come to write the setlist in the early evening, having checked in like this will help a lot.

Then Janette and I, along with Richard and his wife Rachel, and Mr Wickham (no longer questioning the point of wellington boots, his polka-dotted ones firmly on his feet), ramble out into the world of the festival.

Soon of course, as happens at festivals, we lose each other, and Janette and I stroll through the crowds up towards the very top of the festival, to the Green and Healing Fields and the final space, the King's Meadow up at the top of the hill overlooking the whole vast site.

On the way we pass many fantastical totems and creations - vast wicker statues, wooden animals, a massive black and white cow statue upside down on top of a pole - and little set-up shops and gypsy caravans selling all kinds of wonderful items - wall gargoyles, gas lamps, military tunics, peace-painted jerry helmets, fancy vintage lace dresses, tambourines, top hats, bronze carvings, wicker artworks, bows and arrows.

At the King's Meadow we encounter the famous/notorious Banksy "installation". Oh how much recent human folly has been committed in connection with that misused word! Banksy's - as you must be aware if you read the British papers - is a Stonehenge-like circle constructed out of old portable toilets. I greatly respect British modern art for its unswerving commitment to preserving the noble and ancient tradition of the Emperor's New Clothes - a courageous and selfless service, especially when one reflects that its works will go unremarked upon by history - but it must be said that Banksy's circle is not without presence (though this is in some degree because it has been comprehensively graffiti'd by festival punters). As we walk past it, a chap dances in slow motion on top of one of its portaloo megaliths to music playing in his own head, stripped to the waist, body-painted, blissed-out, the Avalon sunset providing a red-gold backdrop. It is like a scene from a post-apocalyptic 'b' movie starring Dennis Hopper.

We wander for a good couple of hours and on our way back towards the backstage area I pass a stall selling vintage clothing. A magnificently battered tall top hat (a "stovepipe" hat) catches my eye. I try it on and it looks impressive in a debauched ringmaster-crowman-Bill-Sykes kind of way. I'm tempted to buy it until I check the price. Seems a little over-priced, but I am no good at bargaining and bartering, so I leave it.

I call Wickham on the mobile. He is a terrific barterer and if he's close by I'll ask him to come and negotiate with the stall-owner for me. But I only get his answering machine. Then I spot a familiar figure ambling through the crowd. It's our drummer Damon, that superb chap. I call to him, and when he comes over I ask him if he is any good at bartering. Turns out he is, so together we head back to the stall, and Damon embarks on a very excellent routine of trying the hat, being unimpressed, then unsure, putting it back, and then, just as he's on the point of leaving, turning and saying "well, would you take an offer?"

The lady of the stall would, and does, and the transaction is completed to everyone's satisfaction. We walk away one stovepipe hat better off - and it will be worn tonight, extending my height by a foot, as we take the stage and launch into Fisherman's Blues at roundabout 11.30pm.

TWO: Saturday 23rd June (early morning)

When we play Glastonbury we always stay in a hotel some miles from the site. Camping is not for Mr Scott, and I prefer to have a peaceful space to prepare for the show and to sleep afterwards. As we're playing on all 3 days of this year's festival, it means we are in our hotel for four nights - so we are quite comfortable, and conserve our energies for the daily expedition into fortress Glasto, where we explode/detonate/erupt on stage.

After our first show at the Avalon Stage, therefore, we are back in our vehicle, ready to leave the site at 1.30 am. There's a snag though. The nearest main drag is the route to the Field Of Lost Vagueness, one of the few Glastonbury venues still open in the small hours, and it is filled with people. No vehicles may pass. So we are held up for two hours waiting for a festival steward to give us the all-clear to move off.

Tour Manager Dave "Killer" Conroy won't let us stray far, because we may get this all-clear at any time, so our post-gig forays into the brightly-lit magical night of the festival are few, and short, but Damon and I do manage to make an expedition into the parallel world of the Tipi Field. It is a truly amazing sight: around a hundred full-sized white tipis erected in a circle round an open green space with a fire in the middle, like an American Indian village. What a presence the tipis have - round, majestic, spiralling to the sky, smoke rising from their flaps, lights within from gas lamps, candles or bonfires. Yet, as if to remind us that this is 2007 Glastonbury, to one side of the field, nestled among the tipis, is a dance tent, with 1960-70s disco music ('Stayin' Alive', 'Upside Down', 'I Want You Back') blaring.

In another little tent is a bar where two mellow fellows are serving tea, wine and hot chocolate. "Fancy a hot choc?" asks Damon. Well, I don't mind if I do, mate. So we stand in line in these ideal surroundings as one of the MFs prepares our drinks. There is a plate of what look like chocolate squares sitting beckoningly on the counter. "How much for the chocolates?" asks Damon in his aussie accent. "They're fudge" says the MF, "three for a fiver or two pounds each". We're speechless. Two quid for a little square of fudge!?

Even so, I consider buying one for Janette. She loves fudge. I almost do it, fingers turning the coins in my pocket, but no, something about it just doesn't feel right. We get our hot chocolates and go back to the van.

Shortly after we finally receive the all-clear to move off and so begin the long, slow procession out of the festival, past revellers heading to the field of Lost Vagueness, or weary out-of-it people trying to find their tent. There's one guy dressed like one of the Riders From Rohan out of Lord Of The Rings with a golden helmet and cape, another guy in a (still clean) white suit, shirt and red tie, a girl with the longest pigtails I've ever seen.

In the van Damon and I are telling the rest of the band about the two-quid-a-piece squares of fudge, until that experienced man, Mark Smith, drops the revelation that these would have been, in fact, hash-fudge cakes. The penny drops! I realise Janette has had a lucky escape. Never having taken a drug in her life, or having even smoked a cigarette, I almost gave her a hash cake!

As we clear the festival boundary the dark night is beginning to soften to deep blue in the midsummer sky. And as we drive up the entrance to our hotel, forty-five minutes later, the golden pink of dawn illumines the morning.

THREE: Saturday 23rd June (evening)

On Saturday night we're headlining the Acoustic Stage, and we drive onto the site in the early evening, through the crawl of a thousand checkpoints. My favourite is manned by a superbly upright fellow whose colleagues refer to him as "Taff". Taff has a real style about him, and an unusual way with words. He directs our driver Will to "take a left and stop when you see the woman with the red tabard".

Tabard?! Tabard?! A tabard is an ancient gaelic word for a coat or cloak. I ain't heard that word since 1345!

Several twists and turns later and we are in the festival itself. It's tough manouvring the van up the hill to the artists' entrance behind the Acoustic Stage. By now the mud, swirled and matured by the tender attentions of two hundred thousand pairs of feet, has deepened into a mighty, cosmic, all-pervading gloop - and the vehicle's wheels can't easily get or maintain a grip.

Consequently we have to drive at - for a festival - the unsociably fast speed of 7 or 8 miles an hour, which deeply annoys several pedestrians with a robust anti-car bias who yell at poor beleaguered Will as he tries to do his best. Tour Manager Dave "Killer" Conroy mutters underneath his breath something to the effect of: "all right mate we'll just f**k off like you say and then you'll have no entertainment." Yes, it's all good clean muddy Glasto fun!

Backstage there's a happy reunion because our old bass player Trevor Hutchinson has just been playing with Eric Bibb. Trev, like Steve Wickham and myself, is a survivor of the Waterboys' late 80s albums and tours. He is as tall as ever and looking well; still, surely, the handsomest man in Ireland.

We're also met by Leo Abrahams, who played lead guitar on our new album Book Of Lightning. Leo will play 3 songs with us tonight, lining up onstage between Steve and myself, and a pretty darn good fist he makes of it too, cranking up the volume on his Mesa Boogie amp and nearly blowing my ears off, as he lays into the sonic detonage of It's Gonna Rain and Love Will Shoot You Down.

I glance over at him mid-song and he smiles back at me, blonde haired, in pale shirt and blue jeans, looking like a young farmhand, innocent as a babe, while tossing out switchblade sharp guitar licks worthy of a grizzled Richards-esque rock and roll vulture.

I have my new stovepipe top hat with me onstage. There it sits behind my amp on Damon's drum riser. But a Scottish bloke in the front row has been shouting "put on your hat!" at me since the first number, and just to be contrary, I leave it where it is.

Aftershow "Killer" Conroy makes sure we don't get held up for several hours like the night before, and, led by a helpful steward, we get off site sharpish and back to our hotel. And a good thing too: after only a few hours sleep we'll be back on Sunday morning for our third ascent up the mountain: a lunchtime show on the main stage - the legendary Pyramid.

FOUR: Sunday 24th June

And so, dear friends, it is once more into the breach for your heroes. On our way to the Pyramid Stage, where we perform today, we once again undergo the torture of a thousand checkpoints. And here, reliably, is Taff - though today, to my great disappointment, as he directs us to the next checkpoint he doesn't say the word "tabard".

As we drive slowly though the festival I see the mud has expanded infinitely. It is now a great sleeply gloopy passive ocean, mocking the ragged humanity that squelches through it. I even see some poor souls still struggling in its soup with plain shoes on. One guy drags his legs through the mud, jeans trailing, brown to his arse. I wonder: why didn't he buy some wellie boots on site? They're available, they're not expensive. Is he broke, a luddite anti-wellie hold-out, or simply too out of it to care?

I'm grateful for my own wellies. Here, in this mud-tastic environment, boots are power. I'm reminded of the advice the concentration camp survivor receives in Primo Levi's book The Truce - that the most fundamentally crucial thing to obtain in a warzone is not food, drink, shelter or even a gun. It's a pair of good boots. The man with boots can find all the others. The man with no boots can do nothing.

It's raining as we arrive at our portakabin dressing room behind the Pyramid Stage, that instantly recognisable, pale silver, spire-topped construction that has become a part of British musical legend. I've played the Pyramid Stage five times before: 1984 (we were wide-eyed new boys, amazed at the scale of everything), 1986 (a milestone show for us), 1989 (a downbeat country and western roots-tinged performance), 1994 (two songs guesting with my Liverpudlian pal Ian McNabb and his back-up band, the mighty Crazy Horse) and 2003 (a forty-five minute romp through our back catalogue).

Today, however, as Steve Wickham and I slip behind the stage and sneak a look out, we are dismayed to see that only a small gaggle of punters is gathered to watch the act before us, Corb Lund.

Back in our portakabin, then, as I work on the setlist, imagining us playing to the the same tiny gaggle of punters, I feel as if I'm walking to my execution. Where are all the Waterboys fans?

It's a very hard setlist to write. I simply can't tell what the show is going to be like, or what it needs to be like, so I go for a loose song selection with no running order. All I know is it will be rooted in our new album. I'll choose and call the songs onstage one by one as we go.

We walk to the stage across great stone slabs which have been plopped over the mud to allow artists easier access. I'm still wearing my wellies, partly through solidarity with the audience, and partly because it's such a fag getting them off, cleaning the mud off my hands, putting on a pair of smart stage shoes, and then after the set putting the boots back on again.

We walk up the ramp and from the rear of the stage we can see that since we last looked, despite the rain, the audience has grown significantly. A great sea of expectant faces ranges from west to east and up the hill. We shall go to the ball!

And we do. Liberated from our expected and imminent execution, we relax into our performance and play the best of our three shows at this year's festival; in fact it's my favourite Waterboys Glastonbury show ever, along with the one from 1986.

During Everybody Takes A Tumble I throw in several verses describing my previous vists to the festival. And as I sing and play I can feel the energy of the Pyramid Stage begin to move through me: a thin white fire coursing through my centre, inspiring and informing me how to sing, which way to phrase my lyrics, what song to play next, what shape to throw. Instead of playing, I am being played BY the Pyramid Stage, by the spirit of the Glastonbury Festival, like so many other artists have before me; like I myself have during past performances here.

Yes, I remember this exact feeling: a sustained sensation full of power, music and communion with the audience, unique to this stage, this festival. It is a gorgeous experience, a true privilege.

To my delight, at the end of our closing number, Fisherman's Blues, the audience twirls with Wickham and me during the final fiddle solo; double 360 degree turns during the drum fill at the end of each line. It's a heart-warming sight, and confirmation of the communion between band and audience I've felt during the performance.

Aftershow I eat a chip buttie with tomato ketchup in the catering tent while listening to the reggae sounds of the Marley brothers playing Get Up Stand Up, One Love and Jamming.

After I do a short interview with the festival's website in the media enclosure, our party prepares to leave the site for good. As we put our bags in the van Shirley Bassey's landrover passes on its way to backstage. I hope she feels the same fire on stage as she belts out Goldfinger and Hey Big Spender.

And what of us? Bassman Mark Smith has left already in the crew bus. Richard Naiff and his wife Rachel and my Janette are heading back to the hotel. Damon Wilson and his wife and kids are driving back to London. And that leaves two men standing.

Wickham and I get dropped off in Glastonbury town where we spend a pleasant two or three hours rummaging around the book stores and the witches' shop where Steve bought a hare statue in 2001. We also make a pilgrimage up the mighty Tor, from the peak of which the festival site is visible, nestled mat-like between low lying hills, colourful in its intensity and diversity. The larger stages and tents are clearly discernible, and the boundary wall and some of its rows of high flags can also be distinguished. It is a vast, impressive spectacle.

And yet, and yet.........in the greater panorama of the west country which lays before our eyes - stretching to Wales and the Severn river in the far west, southwards to Devon, northwards along the line of the Mendip Hills, eastwards towards Wiltshire, pockmarked with towns, churches, cathedrals, fields, farms, rivers, rooftops, water-cuts, monuments, ridges, hills, mumps and burrows; a strange, ancient and vast tract of England - the Glastonbury Festival is but a mirage, a three-day Brigadoon appearing out of the mists; a mere temporal moment in the mighty lifespan of the nation.

But what a moment!