London Philharmonic Orchestra/ Nezet-Seguin, Royal Festival Hall

Conducting is a mystical business. You generally know within seconds of the start of a performance if he or she has what it takes to take an orchestra and an audience to that other place where senses are heightened and the air seems to move a little differently.

The word has been out on Yannick Nezet-Seguin for a while now but it was the performance of Ravel's La Valse at the start of his first concert as Principal Guest Conductor of the London Philharmonic that will have convinced a lot of people, myself included, of great things to come.

The erratic heartbeat at the start of the Ravel drew all ears into a strange nocturnal netherworld where murmuring bass voices grumbled and sighed. The emergence of the once-glorious waltz had the sickly-sweet smell of death about it and in exaggerating the rubatos and agogic hesitations of the familiar Viennese style it was as if Nezet-Seguin was holding a distorting mirror up to the music and showing us its imminent collapse. There was a wonderful moment in solo strings where the suggestion of a private soiree was but a fleeting, flickering, memory. The end was terrible in the best sense - grotesque and shocking. This was the moment Nezet-Seguin arrived.

Ace trombonist Christian Lindberg arrived in his customary hurry, signature white shirt flapping in the jet stream. A double-whammy was in the offing. In his own edition of Leopold Mozart's Alto Trombone Concerto a ripe vibrato, wickedly crisp articulation, and even a trill displayed all the agility of a piccolo trumpet. But when he returned in full evening dress to despatch something called Cantos de la Mancha by Jan Sandstrom, suspicions were immediately aroused. Within seconds of commencing a chivalrous fanfare he hurled his trombone to the floor, started screaming at the audience, and ripping at his formal attire. Nervous breakdown or performance art? Both. This "mad scene" for the deluded Don Quixote would have been laughable but for the impossibly beautiful lament at its heart. Lindberg ended up in a pair of leopard skin tights brandishing his instrument's slide like a lance. I'm not quite sure who had the last laugh.

Nezet-Seguin definitely had the last word, a protracted resonance of bells and tam-tam rounding off his richly characterised performance of the Mussorgsky/Ravel Pictures at an Exhibition. Its sensibility was French but the boldness of sonority was entirely Russian with Samuel Goldenberg's pompous oration, for instance, rolling out like Chaliapin's basso profundo.