I’m en route to hear Pavarotti in Pavarotti City, Hyde Park. O Paradiso. Opera buffs cross oceans to listen to him. But will the power of that single human voice send ripples across the Serpentine? And will there be a sing-along?

I brave forth, being stabbed with brollies and thinking of the 10 miles of cable the organisers said they used and the 50,000 ice-creams they anticipated selling. All this for the so-called man of the people – 100,000 of them (and most of them in anoraks) as it turns out.

The ground is strewn with bedraggled people wearing black dustbin bags and media people bearing portable phones. There are also a few City suits. Mrs Cartwright, modelling a noir trash-can liner, had arrived the night before from Shrewsbury. ‘We saw him this afternoon when he practised. He was marvellous. Mind you, we’re not going to see him now’ – she gestures to the crowds. Mr and Mrs Cheeseman, 68 and 72, sit on the damp grass. ‘We’d have come here in the snow.’

The splendid pink, red and columned stage stands beneath a grey sky – 70 feet wide and 200 tonnes of Greek (pop-gone-rococo-style) theatre. It’s 5.30 pm – and the crowds at the front are as thick as at a pop concert. Above a helicopter hovers and speakers hang suspended from cranes. There are also three 30 ft Starvision screens and an Oriental wholefood bar (among others) which seems to have attracted a fair crowd.

John Major arrives on the screen, with a brolly crumpling over him. Then Charles and Diana arrive. She appears to be wearing an umbrella. The atmosphere becomes wet and expectant.

Now it’s 7 pm. The great signor, the wow-ee vocal artist, The Voice with the massive midriff is about to appear. This is the loudest man in London, the maestro, a natural phenomenon and the best tenor in the world . . . and to herald his arrival, the heavens open.

I’m as close to the stage as I can get, about a quarter of a mile away, I fancy. And there I am, waiting in the drenching rain looking at shoulders and umbrellas, corporate and otherwise. It’s like standing under an overflowing drainpipe while people start to look as if they’ve been in a communal carwash.

There are claps and cheers – so apparently He’s arrived. ‘I’m not sure the acoustics are very good,’ says Jackie Rennie, who types for Kenneth Baker and wears a PVC mac, standing in the al fresco crush bar. Something to do with the ceiling, perhaps? ‘He’s lost his voice,’ says somebody else. And it’s true, you can hardly hear him.

Ten people sit under a home-made plastic tent, occasionally coming up for air. Now the rain has let up. ‘Down, down, down,’ howls the crowd – talking about the view-obstructing brollies. Now I push forwards, up closer to the place where they say things like ‘Shhh’ – and don’t talk while he sings. Ahhhh, Puccini.

The big voice fills the big space marvellously. Here, I hear the tenor of the century – unique, strong and honeyed – issuing through speakers at the back that don’t synchronise with those at the front.

Then Pavarotti says: ‘I ‘ave never seen a woman like that. I would like to dedicate this to Lady Diana.’ At least, that’s what it sounded like. The teenagers around me are drinking Pils and saying ‘Go on Placido’ and ‘In’t he fat?’

The park is starting to smell of damp jumpers but there’s excitement in the air. A cry goes up with O Sole Mio, the ice-cream cornetto song – one feels the raspberry ripple of enjoyment in the crowd.

It gets the biggest cheer and a few bravos. Then there’s a whirl of approval and clapping when we move into Nessun Dorma, the World Cup song – and huge applause before he finishes.

At 9.50 pm, people begin pushing under the plastic cordons. Then they start leap-frogging the metal barrier. The orchestra goes off. One assumes Pav has too. And a big boo goes around the park. ‘Not the best thing in the world, but good fun,’ says a soaked lady.