A summer’s evening in mid-July in the leafy suburbs of south-west London, and we’re queueing patiently outside Hampton Open Air Pool – and to those of us who live in the area, this is a very special place: an old-fashioned lido-style swimming pool which is heated and open 365 days of the year. You can swim there on Christmas Day (as I have) and New Year’s Day, you can swim on a weekday evening in April and have the pool almost to yourself, you can sunbathe on the terrace, or on the grass by the pool, and in the summer you can hear jazz legend Courtney Pine perform there.

I heard Courtney Pine at the pool two summers ago, and he and his band were magnificent. It was my first proper experience of live jazz. For someone who spends most of their concert life inside the rarefied surroundings of the Wigmore Hall in hushed reverential silence, jazz played by a UK jazz legend in the open air was something else, and I was completely blown away by it. Not just his fine skills as a performer, but also his generosity of spirit, introducing each member of the line-up in turn and giving each musician a chance to shine with solos and improvs – and they are all highly talented and very committed musicians.

Two year’s ago it rained, that fine rain that doesn’t look like much, but leaves you quickly soaked. It is a tradition at the Hampton Pool open-air concerts to bring a picnic, meet friends, share food and wine, and wait for the musical event of the evening to begin. We huddled under raincoats and umbrellas, passing food in tupperware boxes along the line of camping chairs, and in true British ‘Dunkirk Spirit’ dug in for a cold, wet evening. The ticket price at Hampton includes a swim, and despite the rain, my son spent most of the evening in the pool, until turfed out by the attendants. Then he surprised us by going right down to the front of stage and strutting his funky stuff, holding his hands up to Courtney. Fortunately, the rain stopped by the time the band took to the stage and we warmed up by hand-clapping above our heads and dancing energetically.

Yesterday evening was perfect: the sun came out and we had our picnic in the last warming rays, while big fluffy clouds scudded high above the stage and the occasional aeroplane shimmered in the clear evening sky. The feast laid out on the picnic rug at our feet was a joint effort, a kind of ‘pot-luck picnic’, and we enjoyed homemade falafels, venison pate, smoked salmon, Serrano ham, and my delicate green pistachio macaroons. Wine was served in a plastic jug in plastic glasses, beer was swigged from cans, people talked and laughed, sprawled on the grass, or settled into their picnic chairs. A typically English summer scene. Meanwhile, my son was diving into the pool, over and over again…..

The warm-up act was a Scottish singer called Eileen Hunter, who had something of Cleo Laine in her voice, and sang some forgettable, but pleasing-on-the-ear tunes, music more suited to the end of an evening in a jazz bar, the lights low, a weary barman cleaning up, pausing in his work to listen…… With my current obsession with Gershwin, I was more interested in getting a look at her hands on the piano, to see if I could pick up any technical tips.

The main event began with deep, rasping notes on the bass, shimmering cymbals and snare drum, some notes picked out on the piano – and then, seeming far away, the unmistakable throaty voice of Courtney’s saxophone. Thus, began nearly two hours of the most enegertic, passionate, raw and committed music-making. Courtney explained that his latest tour was a ‘hommage’ to Sidney Bechet, and many of the pieces he played were from his latest album, some familiar, some unknown. What I loved about the whole performance, aside from the music, was the way the musicians interacted. Watching string players in a quartet, you see the eye contact, the little nods and winks, the feet keeping time, and you sense their connection. It was the same with the musicians on stage last night: you notice that they are all watching each other, waiting for cues, listening, marking time before their solo. There were laughs too, some private shared joke between the drummer and the pianist (the amazing Zoe Rahman), who was laughing so much at one point, she had to stop playing. You sensed their sheer enjoyment in the music, as well as their deep commitment.

Toes tapping on the grass, hands clapping, wine glasss at our feet, one felt the audience, still rooted to their camping chairs, wanted to get up and dance, but were a little too restrained; nice, middle-class, middled-aged people just don’t do that! Or do they?

The final number was a sort of ‘township jive’, and soon, urged on by Courtney, everyone was on their feet, dancing, clapping, waving, all our middle-class, middle-aged inhibitions cast off (“we were wild, in the old days”, as Joni Mitchell once sang). Courtney left the stage, still playing, weaving his way through the moving crowd. I turned, and there he was, in front of me, grasping my hand in his, still playing…. He gathered a crocodile of people behind him, and together they Conga-ed around the grass at Hampton Pool, while the rest of us carried on dancing.

It was a wonderful evening, and he is a wonderful showman, who clearly loves what he does, a superb saxophonist and a fine flautist too. And I’m not sure there are many performers who would lead a Conga around a suburban swimmig pool! We left on a high, picking our way through the debris of other people’s picnics to the car.

“I’m going to the Wigmore tomorow night, for an evening of Chopin,” I told my friends as I said goodnight to them. “From one extreme to another!”

Yet, I have a feeling I will experience something of last night’s performance in tonight’s………though perhaps without the Conga.