The invisible man Wish you were here

Music: Brggen / Harnoncourt Barbican, London

We may disapprove when conductors show off, but do we want them to be completely self-effacing? It was only when the soloists walked on to the Barbican stage for the performance of Bach's Mass in B Minor last Thursday that I noticed that the conductor, Frans Brggen, had quietly materialised on the rostrum. By the time the singers had returned for the applause at the end of the first part of the concert, Brggen had vanished.

If the performance had been of exceptional quality, this might have looked like laudable modesty. But it wasn't: the Tallis Chamber Choir and the English Chamber Orchestra sang and played efficiently, and yet there were few thrills. Gustav Holst tells us that when he first heard the Sanctus he had something close to an out-of-body experience. This was more like being driven down an autobahn in a BMW - you know you're going very fast, but you don't feel it.

At his best Brggen can be one of the most purely musical of today's period-style-conscious conductors: in his refusal to behave like a typical modern conductor he may be the most"authentic" of them all. But here he failed to galvanise choir, orchestra or soloists. Tenor John Mark Ainsley sang with his usual ardour and feeling for phrasing, and alto Derek Lee Ragin worked hard to give his phrases shape, but the rest of the team were disappointingly cool.

Maximum contrast was provided at the Barbican the next night when Nikolaus Harnoncourt - pioneer of the "period style on modern instruments" movement - conducted the Vienna Symphony Orchestra. First came Haydn's London Symphony. I can't remember ever hearing the slow introduction to the first movement as powerfully expressive or as dramatically pregnant. There were plenty of Harnoncourt idiosyncrasies - the extreme contrast of tempo between the Minuet and the Trio, for instance - but it was all done with such conviction that to complain seems like quibbling. Pianist Rudolph Buchbinder was a much less exciting soloist in Mozart's D minor Piano Concerto, K 466, though even there Harnoncourt's insights could be enjoyed.

Finally came a performance of Beethoven's Pastoral Symphony that showed again what an original, heart-felt masterpiece this is. As with the Haydn, purists could have had a richly enjoyable time taking offence at this detail or that device. Those for whom great orchestral playing is simply a question of "sound" might bridle at Harnoncourt's sharply featured phrasing, or his bringing out of inner voices and colours within the texture. But the Pastoral emerged as a wonderfully vivid musical landscape and a very human dream. Beethoven called it "more an expression of feelings than a tone-painting". Here, you could see what he meant.

Stephen Johnson