Can it really be nearly 25 years since Nigel Kennedy’s landmark first recording of Vivaldi’s Four Seasons? 1989: when Baroque music adopted commercial pop’s mass marketing techniques, selling over two million copies (with a place in the Guinness Book of Records for all-time best-selling classical work) and making the young chap with lightning fingers and sticking-up hair a media sensation. I remember it coming out: as a teenager, it was a revelation (Vivaldi = not boring after all!), and it was my favourite album for some time. For this concert, the BBC Proms Guide promised “fresh insights to these visionary concertos, including the addition of his own improvised links between them”, but delivered so much more – a riot of imaginative, witty, Arabic-jazz-Baroque joy.

Spring began in a fairly straightforward manner, albeit with more slapping from the basses than is customary, and the percussive, multi-textural elements of the music brought to the fore by Gwilym Simcock’s piano continuo and Krzysztof Dziedzic’s percussion. The Red Priest may not have written heavy use of hemiola polyrhythms into his accompanying figures, but I do believe he might have approved on hearing them. Alongside members of Kennedy’s own Orchestra of Life, the performers were from Palestine Strings, an ensemble which draws from the Edward Said National Conservatory of Music, where students are trained to be bi-musical, so to speak – equally at home in Western classical and Arabic musical traditions – and throughout the work, select movements of the Vivaldi were used as springboards from which several of the young players gave brief cadenzas (one sung rather than played!) in their own fluid, microtonal style. All were lovely, but the viola solo shone out with particular beauty.

This emphasis on an ensemble of diverse individuals, and the ever-changing musical relationships between them, was precisely the opposite of the manner in which one frequently sees these concertos performed: the lonely soloist with distant gaze, floating aloof above a perfectly homogeneous rank and file (not that there is anything wrong with this style of performance; all have their place). This soloist spent most of the time with his back to the audience, moving around the better to engage and duet with various members of his ensemble.

Summer provided a diversion in a different direction – to another Kennedy favourite, Duke Ellington – while Autumn included a passage indicated in the score (according to the programme notes) as “Swing Improv on F Mixolydian”, and an Adagio molto that upgraded the peasants’ wine (in Vivaldi’s text) to something hallucinogenic-sounding and probably illegal. However, the anarchic presentation of this genre-bending panoply belies the fact that while improvisation was an integral part of the music, the underlying structure within which it could flourish was clearly carefully judged in terms of large-scale harmony and tempo ratios. Winter, finally, was left the most structurally intact. No more twittering birdsong, muezzin calls or lazy summer-evening jazz: Kennedy revved the engines and laid into the solo violin part with the blistering fury of the Sirocco, Boreas, and all the winds in conflict. This is winter; these the joys it brings.

This was not a performance for musical purists – or was it? Kennedy’s stand on performance practice is that “True, authentic playing involves using whatever sound is most relevant to enhance the mood”. This mood of this performance was full of the pure joy of making music with friends, carrying learning lightly, and allowing oneself to be playful with well-loved pieces. Personally, it took me right back to 1989, before music became such a serious business; a teenager bunking off hated PE every week with a couple of friends from my GCSE music class (main study work that year: Vivaldi’s Winter) to hide out in the music practice room, playing and improvising over any and all music we could find, on an ad-hoc ensemble of flute, saxophone and a battered piano that had detuned to Cageian levels.

The scheduled end time for the concert had come and gone, but with the majority of the audience showing no inclination to run for their last trains, the players found the energy for two encores: a movement from a Vivaldi double violin concerto (performed with Kennedy’s own newest protégé, 15-year old Mostafa Saad), and an own composition, the filmic Fallen Forest.