Whenever one of the top conducting posts in London falls vacant, Mariss Jansons is the first name on everyone's lips. But after 21 years in charge of the Oslo Philharmonic, where he raised an average orchestra to world-class status, he is now music director of the Pittsburgh Symphony, and in 2003 will take up the same post with the Bavarian Radio Symphony in Munich. For the foreseeable future, then, he's only likely to appear in the UK as a guest.
This week he is conducting three programmes with the London Symphony Orchestra. The first concert was exceptional - at a time when conductors of the highest class can be counted on one hand, Jansons unquestionably belongs in that elite. It was a perfectly ordinary programme of Brahms, Mahler and Ravel, made extraordinary by the intensity and insights that he brought to all three composers.
Brahms's Third Symphony has become almost a rarity in the concert hall, perhaps because it lacks the grandeur and noisy conclusiveness of his other three symphonies. But Jansons's view was absolutely compelling. He shaped the opening in broad, sweeping phrases, coaxing pianissimos of exceptional purity from the LSO in the andante, and gave an unusually measured account of the third movement. Brahms is not usually prized for his orchestration, but here the interleaving of the layers in those central movements was turned into a thing of wonder.
Every element in the sound picture was exactly integrated. The pungent clarinets that launched Des Antonius von Padua Fischpredigt - the first of four numbers from Mahler's Des Knaben Wunderhorn, sung by baritone Thomas Hampson - defined the whole droll mood of the song perfectly; the twin, contrasting worlds of Der Schildwache Nachtlied were conveyed effortlessly. In Revelge, both the echoes of Mahler's Fifth Symphony and anticipations of Kurt Weill were touched in with perfect naturalness. Hampson was equally precise and telling in his characterisations, and as his evenly sustained pianissimo to end the Nachtlied demonstrated, his voice was in fine fettle.
To end it all, there was a tumultuous performance of Ravel's La Valse. Jansons steadily ratcheted up the tension until the explosion of the final cataclysmic pages, and the combination of suavity and scarcely suppressed violence was bewitching. The LSO's playing was exceptionally vivid, and Jansons's control of every rhythmic detail almost miraculous.
Further performance on Sunday. Box office: 020-7638 8891.