The Proms are upon us again. This year – Nicholas Kenyon’s last as director of what is routinely but accurately described as the Greatest Musical Festival on Earth – is particularly succulent, every page of the programme crammed with something unmissable, whether the Vienna Philharmonic, opera from Glyndebourne, medieval church music or jazz. It may not all be to your taste, but the existence of such wildly diverse elements side by side creates an uncommon degree of creative energy, hilariously at odds with the grandeur of the building in which it takes place. All through the summer, under the golden gaze of Prince Albert, that extraordinary mausoleum on the edge of Kensington Park heaves and buzzes and explodes with reckless vitality.

I’ve been going to the Proms for more than 40 years and watched it evolve almost out of all recognition. The year I went to my first concert, 1964, must have been the high tide of the old-style Prom. Malcolm Sargent still presided, superb in perfectly fitted tails, starched white waistcoat and bow-tie, a carnation in his lapel, his hair slicked and shiny. He was a famous ladies’ man, and there was a not unattractive touch of the gigolo about him. On the podium he was stunning, spine inhumanly erect, mouth set in a moueof masterful self-confidence, baton bristling dangerously like a porcupine’s quill. Back then programmes lasted almost twice as long as they do today, coming in at two-and-a-half or three hours, nearly up to Victorian proportions – one of the things that provided the direct link one so strongly felt to the founder of the concerts, Henry Wood. His bust was prominently displayed at the back of the platform, lit, for some unfathomable reason, a lurid green. There was something tremendously solid and nononsense about his appearance, bearded and vigorous, a sort of musical James Robertson Justice. No doubt because the arrangement of the Sea Songs that provided the climax of the Last Night was his, he seemed to possess a nautical air, Captain of the Good Ship Classical Music. And yet this bluff looking chap was giving the first British performances, weeks after they were written, of fiendishly difficult pieces by Strauss, Schoenberg, Stravinsky, Shostakovich. During most of Wood’s 50-year-long presence at the helm of the concerts, they took place in the Queen’s Hall, in Portland Place. When that acoustically perfect venue was bombed during the Second World War, the operation transferred to the Albert Hall.

For me, the venue was very much part of the magic of the event. I certainly had no way of identifying it as such, but the building was high camp. Architectural Victorianism had not yet been rehabilitated, but everyone had a soft spot for the Albert Hall and its mad excess. What did we care that even the most massive forces were sonically dwarfed in its vast open spaces (though, oddly enough, quiet music registered with exceptional vividness)?

The spectacle was thrilling, the sense of occasion unparalleled – the riot of red and gold, the tiers of curtained boxes rising up to the mighty dome, the foliage and fountain in the middle of the promenade, again lit by a madly incongruous brothelesque kaleidoscope of lights, which lent a louche air; somewhere in the background was the fact that boxing matches took place in this same arena. There was nothing stuffy about the Proms, a startling contrast to concerts elsewhere in London, where dinner jackets and tiaras were the norm. That was true then and it’s true now.

Though I came up to Kensington regularly throughout the season, I was never a Prommer, properly speaking. I was a loner and they were a gang, coordinating their stunts, painting their banners, sharing a sense of humour and a set of tribal chants, rather like a sort of genteel football crowd. What was impressive, almost uncanny, was the way in which they would fall into rapt silence the moment the music began. Being, rather like Sargent, on the conservative side, they often disapproved of new pieces. I have a vivid recollection of copies of the Evening Standard being ostentatiously (though noiselessly) read during the British premiere of Messiaen’s sublime Et Exspecto Resurrectionem Mortuorum; when the tam-tam player lost his stick at the climax of the piece and it flew into the promenade area there was a triumphant roar of laughter. On the other hand, they took Penderecki’s St Luke Passion to heart, and he must have been heartened by the mighty shout with which they greeted his appearance on the platform. Now the majority are as open to the new as they are raucously receptive to the old – don’t miss your chance to join their ranks with The Times’s offer on this page.

Thanks to a succession of BBC controllers, an agenda for the transformation of the British musical scene was under way. The arrival of Pierre Boulez as chief conductor of the BBC Symphony Orchestra signalled a definitive revolution: his fierce intellectual glamour erased the spirit of Sargent. Even so, a new spirit of inclusiveness and of diversity had already replaced the curious mixture of the hearty and the devotional that had characterised the Proms, its alpha and omega the final Friday rendition of Beethoven’s Ninth and the Last Night. Now the Ninth is just one of Beethoven’s symphonies, which in turn are just some of the examples of that genre, which in turn is just one genre among many in the Western tradition, which in its turn is just one tradition among many, while the Last Night is now almost terminally ironic, a sort of classical Rocky Horror Show.

But the success of the Proms does not depend on the Last Night, or any one concert. The Greatest Musical Festival has reached a high point of brilliance whose only real agenda has been to open up our ears to the contents of an Aladdin’s cave. How extraordinary that it exists.

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