The band, he said, were "fat, 40 and back", which was a succinct, if overly modest, analysis of proceedings (even the hulking Steve Jones, who proved the Pistols could still be frightening by taking off his shirt, is sylph-like compared to, say, Shaun Ryder). Finally, Lydon chanted: "We're the Pistols, no one likes us ... and we don't care!" What? What do you mean no one likes you? There are more than 30,000 people who like you so much that they've paid pounds 22.50 to crowd into Fins- bury Park. True, most of them are wearing Stiff Little Fingers T-shirts and trousers whose legs are tied together, but superannuated punk fans are people, too, you know.
The Pistols, in denial about being a revered rock institution, are nostalgic for the good old days when they were unpopular. At the start of the show, they ripped half- heartedly through a paper curtain printed with 20-year-old head- lines which branded them "Foul Mouthed Yobs". Nowadays, short of being naturalised as Germans, they could never elicit that kind of tabloid venom.
No, the only people who really dislike the Pistols today are the people who think their heroes are spoiling a perfect memory, who believe that the band were staunchly principled scourges of the music industry, iconoclastic shocktroops whose teenage opinions and antipathies should stay with them into middle age. But the Pistols long ago produced an album called Flogging a Dead Horse and a film called The Great Rock'n'Roll Swindle. What exactly is left to be tarnished?
At one of their earliest gigs, the group responded to a heckle that they couldn't play with: "So what?" Whether or not they could play then, they certainly can now. For just over an hour, the old songs sounded better than they ever do on vinyl. The band were tight, thrilling and nasty. They sounded vicious, partly because Vicious is no longer with them. The reinstated Glen Matlock may not be an icon, but he's alive and well and thwacking the bass like Sid never could, which must be some kind of compensation. He's still the sensibly dressed odd one out, though, and he kept his distance from the others, just in case they recalled old animosities and beat him up. They were too busy beating up the music. Steve Jones's crunching guitar reminded us that Noel Gallagher owes as much to the Pistols as he does to the Beatles, while Lydon, the front-man with the most front, was ex-ceptional. He danced, marched, jumped and jerked, his hair a crown of Statue of Liberty spikes. His voice couldn't have quite the same incredible level of arrogance and terror that it had when he was 21, but it was within, well, spitting distance.
And that's about that. What else could we expect? Changes of costume? A string section? Some dancers, perhaps? No, all we were ever going to get was four men playing utterly simple rock songs, but playing them with primal vigour and charisma. They could have tried to be a little less predictable, though. Why play two fake "encores" - sure, you weren't going to play "Anarchy" unless we begged you to come back - except in obeisance to the most aggravating of rock traditions? Still, as the provenance of so much rock tradition is the Sex Pistols, I could forgive even that. "Ever get the feeling you've been treated?" punned the announcer at the end. Yes, indeed. They didn't spoil a memory, they spoiled us rotten.
For the rest of the day in Finsbury Park we could admire the "Old Punks Never Die, They Just Stand at the Back" T-shirts, and pick through stalls selling wind chimes, hemp wallets and candles in the shape of trolls, while wondering whatever happened to the "Never Trust a Hippy" credo. Other bands vied for our attention, but as we were in broad daylight during everyone's set but the Pistols', none of them was entirely successful. The main support act, Iggy Pop, must have a portrait of Dorian Gray's torso in his attic. His face has aged, but he could have easily spent the last few years as a body double for Take That. He played a greatest- hits set, and tested the resilience of a selection of microphone stands by battering them off the stage. They got off lightly compared to the unprintable things he got up to with the speakers.
Skunk Anansie's bionic singer, Skin, still has a voice as piercing as feedback, but the band were rather controlled compared to previous gigs, ie, they didn't do anything unprintable at all. The Wildhearts lightened the tone with their buccaneer rock 'n' roll, and, earlier in the afternoon, the Buzzcocks proved why their name should be the answer offered by Supergrass and Ash if anyone asks: "Where do you get your ideas from?" And they threw their guitars high in the air at the end of their set, as all bands should.
The festival in Finsbury Park the day before was left seeming like a warm-up, and its headliners, Madness, knew it. Chrissie Boy would hit a loud chord, and Suggs would chide him: "No, no, Chris. That's tomorrow." But as the continuing success of the Madstock series demonstrates, Madness are as well suited to these outdoor events as sun-tan lotion and polystyrene tubs of noodles. They're still nutty after all these years, and they have giant tunes that even extra-terrestrials know off by heart. The only letdown, a worrying skinhead presence excepted, was that they played some unremarkable new songs. Careful, chaps. People don't like it if you spoil a perfect memory.
Sex Pistols: Glasgow SECC (0141 248 9999), 16 July.