LPO/Van Zweden, Royal Festival Hall, London

Jaap van Zweden cuts a bullish figure on the rostrum. If music were driven by energy alone, the young Dutchman, one-time concertmaster of the Royal Concertgebouw Orchestra, would be home and dry every time. But he took on Mahler's problematic Fifth Symphony for this much-anticipated outing with the London Philharmonic, and it felt very much like a work-in-progress.

But first came Beethoven – a spry collaboration with Emanuel Ax in the Second Piano Concerto. A playful nonchalance characterised the early stages. Mozart seemed to be watching Beethoven from the wings, as Ax and Van Zweden enjoyed the gamesmanship of one great composer in deference to another. Ax was exquisitely light on the keys, weighing in only slightly to signal those bold Beethovenian modulations.

But then, in the cadenza, came the extraordinary moment when Beethoven finally became Beethoven. Alone in one of his extraordinary improvisations, we were taken to places, harmonically, far removed from the context of the piece. Both here and in the closing exchanges of the richly embellished slow movement, Ax achieved a wonderful remoteness and mystery.

And so to Van Zweden's Mahler. If you can't raise the roof with the euphoric coda of the Fifth, something is seriously wrong. Van Zweden duly did, but in such a way as to leave one feeling that it hadn't been earned.

The performance simply didn't add up. Many factors govern the symphony's journey from darkness to light, but prime among them is the dramatic change in the manner of articulation. The weighty excesses of the first two movements give way, through a scherzo of quixotic magic and menace, to the floated avowal of love that is the Adagietto. But Van Zweden's Adagietto was too heavily inflected (and initially far too loud) to convey its true intimacy, and when Mahler develops elements of that music in the jubilant finale, it's essential to keep the texture light, airy and buoyant. Van Zweden and the LPO made heavy weather of it. It never truly took flight until the final bars.

Elsewhere, the playing certainly had its moments – not least the refulgent horn solos in the scherzo. But here again, Van Zweden made little of its innate charms, to say nothing of pause and silence. So often in Mahler, the magic lies between the notes. Van Zweden hasn't yet found it.