An all-Berlioz concert under the baton of Colin Davis, that doyen of Berlioz conductors, with Tabea Zimmermann and Anne Schwanewilms also in the line-up looked like a recipe for sure-fire success. The success was some time coming, however, and when it did it was qualified rather than thundering.

The concert began with the King Lear Overture, a young man's essay about the travails of old age. Part of Davis's art with Berlioz is his ability to make the fragmentary cohere but even he failed to make an entirely convincing case for the overture's depiction of the tragic unhinging of the king's mind.

The German soprano Anne Schwanewilms has one of the most distinctive and beautiful voices - a light, silvery tone - around today.

She has also made a name for herself in German repertoire, notably Strauss and Wagner. Whether she is equally suited to Berlioz is a moot point. There was some hint of tonal contrast between the carefree opening Villanelle and the more elegiac following songs, Le Spectre de la Rose and Sur les Lagunes.

But the differentiation was not marked enough: all the pieces sounded pretty much the same, partly because Schwanewilms didn't really inhabit the text.

Harold in Italy, the poetic symphony with viola solo (Zimmermann on fine form), depicts, according to the composer, "a kind of melancholy dreamer in the style of Byron's Childe Harold".

But Berlioz is also one of music's great neurotics - he once set out hotfoot for Paris intent on killing both his unfaithful lover and himself.

Davis does melancholy rather than neurosis. But if one missed some of the febrile quality of the music, the triumph finally came with the unerringly paced coda to the symphony, delivered with brio by the dependable LSO.