LSO / Welser-Möst, Barbican London

It always surprises me that Franz Welser-Möst comes back to London after the beating he took (rather than gave) here through the 1990s when he was the not so well-loved principal conductor of the LPO. The temptation, you'd think, would be to shake the dust from his shoes and move on.

It always surprises me that Franz Welser-Möst comes back to London after the beating he took (rather than gave) here through the 1990s when he was the not so well-loved principal conductor of the LPO. The temptation, you'd think, would be to shake the dust from his shoes and move on.

But then he did move on: decisively, to the Zurich Opera where they liked him, and, surprisingly, to the Cleveland Orchestra (America's best) where they liked him too. All of which makes his visits back to Britain occasions for soul-searching.

Did we misjudge him? Undervalue him? Perhaps. The visits back are usually successful and sold out, as was the case when he conducted the LSO in an odd programme of Sibelius's 4th Symphony and the Mozart Requiem. The Sibelius is a hard-to-read piece: dark, evasive, inconclusive, like a voice heard from another room, withdrawn to partial incoherence. So two cheers to Welser-Möst for delivering it with such clarity, transparency and eloquence, drawing a fine cantabile sound from the LSO strings.

But did it mean anything? To my ear it was empty, without muscle and the grainy texture I expect in a Sibelius symphony. It didn't seem to come from Finland. And it didn't follow the dictum that Osmo Vanska (a real Sibelian) cites as the guiding principal behind his far more powerful interpretations: that, as the composer said, the detail should swim in the sauce. Welser-Most provided detail but no sauce: no flow, no eddying force to drive the music forward. It was more like graceful skating on a sheet of ice.

The Mozart, by comparison, was driven like a coach and horses - and despite the fact that, with a few allowances for period practice, it was the kind of Mozart that Herbert von Karajan could have recorded in the Sixties: grand, impressive, big, sung by the full weight of the LSO Chorus who did well in the circumstances to keep their sound so bright and their articulation clear.

It showed why Welser-Möst goes down well in America: he's technically accomplished and he makes things work. But there was too much gloss - the pounding pedal-rhythms of the Confutatis turned into John Adams - and too little sense of inquiry. Or wonder. This was the business of death as done by an efficient crematorium.

The soloists were good: a fresh, dark bass sonority from Alfred Reiter; a voluptuous soprano from Sally Matthews; a consoling mezzo from Pamela Helen Stephen; and a wonderfully fierce urgency from the tenor Mark Padmore.

But the only real interest in the performance was that Welser-Möst tacked on to the end of it Mozart's Ave verum: an exquisite motet written with orchestral accompaniment but normally confined to liturgical use with organ because it's too short for a concert. Inauthentic but a nice touch.