To conduct any orchestra aged 97 is exceptional. To conduct Mahler’s Ninth Symphony aged 97 is nonpareil. Mahler’s Ninth can take 90 minutes to play. It reaches levels of intensity that seem on the edge of the bearable. It probes audaciously into every aspect of the orchestral palette. Yet this is the work that Herbert Blomstedt, visibly frailer than before, conducted in his latest London concert with the Philharmonia Orchestra.

Blomstedt may not seem a natural Mahlerian. His performances of the repertoire he normally favours – Beethoven, Brahms and Bruckner among them – are invariably wise, enabling and balanced. These are not words that come naturally about Mahler’s Ninth. The Ninth is on the edge. It looks into the abyss. It grapples with mortality. But there is room in the world for many Mahler Ninths. Nor was Blomstedt presiding benignly as the Philharmonia played Mahler. He gripped it. He really did.

Try, though, to put Blomstedt’s age to one side for a moment. For this performance required no special pleading. Yes, it took a while to get into its irresistible stride, and the ländler second movement briefly lost momentum. But the hurtling rondo was terrifyingly vivid and the final adagio Olympian. It was one of the finest Mahler Ninths one is likely to hear. And the Royal Festival Hall has witnessed quite a few – my own list starts with Otto Klemperer, a Mahler protege and a youthful 81 at the time, in February 1967.

Much of this was down to the exceptional Philharmonia, who gave what felt at times like the collective performance of a lifetime. The details were stunning, summoned by Blomstedt with a little wave of the arm. To single out the clarinets, trumpet, basses and violas, outstanding though they each were, feels invidious. At times this sounded like chamber music. No one could doubt that they were doing it for Blomstedt, who, like Klemperer, sat to conduct and did not use a baton.

And, oh yes, there was a first half too, quicksilver and quite different, with Leonidas Kavakos, no less, directing a chamber-sized Philharmonia in Mozart’s fourth violin concerto, K218. It was above all an opportunity to glory in the darkly burnished sound of Kavakos’s wonderful 1734 Stradivarius violin. The Italian maestro was 90 when he constructed it. Still learning his trade, like Blomstedt.