London Philharmonic Orchestra / Nézet-Séguin, Royal Festival Hall, London

Two perfect works in perfect equilibrium; Mozart and Mahler well met indeed.

But even as the violin and viola soloists separated from the opening tutti of Mozart’s Sinfonia Concertante in E-flat in perfectly symmetrical octaves it was evident that the conductor for the evening – the gifted Yannick Nézet-Séguin – might have a slightly different agenda.

The soloists in the Mozart – Stefan Jackiw (violin) and Richard Yongjae O’Neill (viola) – were like twins, slight and wiry, soft-grained and refined, precise mirror images of each other visually and sonically. But for all Nézet-Séguin’s attempts to pull back from his natural inclination to enliven and galvanise, to pull rhythm and texture into high relief, the effect was of mismatched collaborators – the dynamic and the effete pulling in two different directions.

To be basic about it, Jackiw and Yongjae O’Neill needed to butch up their acts if they were to compete with Nézet-Séguin’s highly “projected” view of the piece – or vice versa. But notwithstanding the imbalance of sound and personality, the playful interaction of their performance certainly had its moments, not least in the like-mindedness and precision of their fine-spun turns and the rarefied beauty of those almost spectrally withdrawn solo moments. Yongjae O’Neill’s quietly spoken viola had one inexplicably dreadful lapse in intonation just before the close which only pointed up the curious imbalance of it all.

So the fourth star is for Sarah Connolly in Mahler’s song-symphony Das Lied von der Erde and I would add a fifth in recognition of her elevation now into the greats that have taken this extraordinary work to heart. Her lusty companion, drowning his sorrows in the merriment of a full glass, was Toby Spence finding deftness and piquancy where heavier voices find only heft. He certainly had the required “klang” to combat Nézet-Séguin’s “no prisoners” approach. But to my mind the exuberant young maestro was worrying the music too much, accentuating, sharpening, the inner detail of a gloriously responsive London Philharmonic but sometimes to the detriment of a quieter rapture – particularly in the sweet sorrow of that final farewell.

But first and last there was Connolly – great singing so in tune with the watercolour images and their deeper truths. So many shades, such fine detailing. Few have witnessed the renewal of spring with such heightened awareness or better conveyed that through such renewal we glimpse eternity. Glorious.