Oxford is on a cusp at this time of year. The tourist town is giving way to the student town. The bright clothes of summer are turning to the sub-fusc of fall, and academics drift around the streets like autumn leaves. I think Mozart would have been happy here. Oxford opens its arms to welcome the neurodiverse and the hyperfixated. It loves super-talented nerds. Mozart would have fitted right in – and he was the same age as a fresher when he wrote the centrepiece of tonight’s concert.

The 25th anniversary year of the Oxford Philharmonic has been a triumph so far, and tonight was no exception. Entitled Mozart Masterpieces, it featured the Overture to Die Entführung aus dem Serail, the third Violin Concerto, and the 39th Symphony. As ever the venue was the Sheldonian Theatre. No matter where you sit in that building, the acoustics are fantastic, and the music is crystal clear. However I suspect that Christopher Wren designed it with the comfort of the notes in mind, not the buttocks. I did consider offering a fiver to the man behind me in return for letting me lean back against his very comfy-looking legs. But I just didn’t have the nerve.

The first piece, the Overture, was very much an amuse oreille: four-and-a-half minutes of Turkish-inflected oompah-pah. I’ve never seen the opera, but if the overture is anything to go by, they were having a lot of fun in that Seraglio. It was a loosener, and perhaps the percussion was a trifle late on a couple of cues. But they got it together by the end, and the stage was set for Charlotte Scott and her violin.

What a wonderful choice of soloist. Charlotte Scott is the Associate Concertmaster of this very orchestra, and her presence proved that you don’t need to import globe-trotting maestros for a stunning interpretation. To be fair, she has had a stellar career to date by any standards, and after this concerto it wasn’t hard to see why. Scott’s performance seemed to make the violin not just sing, but also speak. It was both melodic and raw; musically perfect but with an underlying wildness – sweet, but with a distinct resiny wail. She wasn’t just playing that violin, she was riding it like a wild horse. And what a violin it was: a Stradivarius built in 1685, it was already nearly a century old when Mozart sat down to write this very concerto.

The second movement, the Adagio, is almost dream-like, with a gentle, throbbing undertone, but then the third suddenly bursts into a traditional Austrian peasant dance (or 'Ländler'). As anyone who has seen Amadeus knows, Mozart loved bringing the vernacular into the upper-class salons of Vienna. Even 'Die Entführung aus dem Serail' caused shock-waves with its saucy subject-matter, and in this concerto the Ländler links the refined chamber piece to the beer-halls of the Austrian Alps. I thought of Julie Andrews and Christopher Plummer who dance a Ländler together in The Sound of Music: the humble nun and the refined aristocrat, brought together by their love of their own culture and their unwitting, nascent love of each other. That's Mozart.

At the interval I noticed what I’ve spotted before with the OPO: they really are the smiliest orchestra you could ever see. At the end of each piece they grin at each other, laugh, chat and whisper. They obviously love their work, and a lot of that must be due to resident conductor and founder Marios Papadopoulos. I have never seen a conductor who conveys so much warmth and avuncular affection for his musicians. If you’ve seen Tár (the film about a conductor played by Cate Blanchett), well, he’s not like that.
It was time for the main course, 'Symphony Number 39; the first of Mozart’s final trilogy of symphonies, all of which he composed in just over two months while he was virtually penniless and unable to feed his family. These pieces – surely among the greatest musical accomplishments of the classical age – were not even commissioned, and were never performed during his lifetime. He wasn’t paid a penny for them.

The opening of the 39th is utterly untypical of Mozart. Rather than the light, skipping strings to which he regularly resorts, here we have deep, long chords, pressing, insistent and disturbing. It hints at the despair and anxiety of his life, which was to reach its ultimate expression in the very next symphony (sadly not on tonight’s programme). But the mood lifts almost as soon as it’s begun, and the movement becomes a mesmeric play of musical ideas. With barely a twitch from Mr Papadopoulos’s jacket sleeves, the orchestra negotiated the light and shade with delicacy and delight.
Then the third movement arrives…. and it’s another Ländler. The hills are alive again, and if you close your eyes you can almost see an old man turning a gaily-painted hurdy-gurdy in a cobbled square in Salzburg. I am no musician, but by the end of this symphony I was transported, and the applause went on and on.

They had to do an encore. And they gave us the only thing that could improve on what we’d already heard… the very next piece of music Mozart composed: the first movement of the 40th Symphony. It is probably one of the most celebrated symphonic creations in western culture, and the pain that was foreshadowed in the 39th hits home with all the melancholy that G Minor can muster. I left feeling thrilled, moved, and, above all, grateful to the OPO. They may not have the clout of the Berlin Philharmonic, but they have heart, passion, humour and a genuine affinity for Mozart, the Oxford student who might have been.