In praise of the back-seat driver

Pierre Boulez chose to celebrate his 70th birthday by passing on a few trade secrets to a trio of tiros. Stephen Johnson was there

"The principle is very simple. It's like driving - just start and stop." This remark, delivered with a characteristic Gallic shrug, marked the high point of part two of Pierre Boulez's conducting masterclass at the Barbican on Thursday. Was it rea lly that easy? Boulez certainly makes it appear so - even if the driving analogy suggests that he knows it isn't. A movement of the wrist, a raising of the fingers, and you feel you know exactly what he means. And so, more to the point, does the orchestr a. Boulez takes the rostrum for a few minutes, and the harmonic structure of the opening paragraph of his Notations is clear as a laser display.

The impression could have been illusory. All three test-pieces had apparently been well-prepared in the morning's rehearsal. But when the three conducting students each took Boulez's place, the difference was striking. The tension, the focus, the steadiness of the beat - suddenly you couldn't take these things for granted any more.

This is not to denigrate the students. To submit yourself to a Boulezian deconstruction in front of a London orchestra and a well-filled auditorium is a brave enough thing to do. To try to realise someone else's precise instructions in scores as challenging as Notations, Stravinsky's The Song of the Nightingale and Webern's Six Pieces for Orchestra under those conditions comes close to the world of the stress-induced nightmare.

And there were moments when one had to ask whether what Boulez was doing really was imitable. There were two priceless examples in The Song of the Nightingale. One student had been coping with the stupendously colourful opening "Fete" section (rather well, I thought) when he came to a seven-bar celesta passage - a colour contrast and nothing more, surely. "No, no, no," said Boulez. "You must understand the rhythms, then it will make sense." He pointed to the celesta, and suddenly the rhythms, subtle andirregular, leapt into life. There was even more fun with a solitary bassoon trill at the end of the "Marche Chinoise". "It's so simple," said Boulez. But it wasn't. From him, it was a stylish gesture - a flourish, a pause for breath, then a tongue-in-cheek resolution. When the student tried it - well, as Winnie the Pooh would have put it, "It just didn't."

Still, there was one major frustration - and, if it felt so to me, how much more must it have weighed on the poor guinea-pigs. All three of them, conventionally, use a baton. Boulez, famously, doesn't. What he conveys with an inclination of his right hand can be immensely significant. After this, the baton tended to look like an encumbrance - almost like a walking-stick on a dance-floor. I understand why a nervous student might avoid confrontation on such an issue in a packed concert hall, but Boulez atleast could have addressed it.

So, in the end, this masterclass did what most masterclasses do, and indeed often seem designed to do - it demonstrated the Master's skill, somewhat at the expense of the students. But it has to be said that Boulez never gave the impression of wanting itthat way. He plainly tried to be helpful rather than patronising (a very difficult balancing act, that) and there were little encouraging gestures - especially the fatherly squeeze of the arm at the end of each session. Could this really be the modernist monster of popular mythology?

Talking to the three brave volunteers after the morning rehearsal, I was struck by how genuinely positive they all seemed about the experience. Two of them described Boulez himself as "very nice" - with a clear implication that not all masters are as pleasant or encouraging. I've deliberately avoided mentioning the students' names until now - my task is to appraise the event, not to try to guess the potential of students under exceptional circumstances. But their comments are worth noting. Harry Curtis (25) says he can see why some people criticise Boulez. "His conducting is very minimalist - it doesn't look emotional. But he shows what you can do if you get the orchestra on your side - if you make it absolutely clear what you want. He doesn't try to make you musical or expressive - if you've got that, it'll come through. If you haven't, why are you conducting?"

Martin West (26) played under Boulez in the marvellous 1987 National Youth Orchestra Gurrelieder at the Proms. For him, it's "nonsense" to talk of Boulez as a "non-phraser" (Hans Keller's pungent description). "He's obviously mellowed with age. And in Notations he really showed us how the lines that are important come through. It was fabulous experience!"

The youngest, the Israeli Ilan Volkov (18), has watched Boulez in rehearsal, but he found working with him much more helpful (a "lovely atmosphere", he says). As for Boulez imposing his ideas, "Well, he wants you to try it his way. You can disagree with it, but it's a valuable experience to try it - not to be a mere imitator, but to incorporate his ideas. I was impressed by how relaxed he made the players feel. You know they're getting the right message, and that they're able to make music much more freely. He doesn't expose his feelings, but I'm convinced they come through - much more than if the conductor's an exhibitionist!" Important lessons all round, for this critic included. Strange that there were so few professional conductors in evidence. You're never too old - or too established - to learn.

n Boulez conducts the LSO: 3pm Sun, Barbican, London (071-638 8891)