The music of Louis Andriessen, Queen Elizabeth Hall, London

This festival celebrating the music of the 63-year-old Dutch composer Louis Andriessen is the strongest confirmation yet that this Sixties revolutionary-turned-musical minimalist has now been accepted as one of the most significant composers of our time. And, if it had started with the riveting account of the mature and vigorous De Snelheid given by the London Sinfonietta under Oliver Knussen that we heard on the second evening, the right context would have been created to examine some of this intriguing composer's less well-known sides as well.

But the festival opened with a performance of the jazz-saturated On Jimmy Yancey by the Steve Martland Band that was so slow that it sapped all this work's vernacular energy from it. And it continued mainly with Martland's own compositions, which have unfortunately now become a model example of how easy it is for Andriessen's pupils to ape his manner without finding enough of their own to say to sustain a compositional career. Andriessen's own late-night improvisations at the piano, with the astonishing Dutch vocalist Greetje Bijma, offered another, if much more compelling, tangent.

The second evening, too, started with a rarity. The most thought-provoking, and, in its way, the most alluring work in Knussen's programme was not the premiere of La Passione, the new composition that gave the festival its title, but Ittrospezione III (Concept II), dating from 1965: an imaginative take on the severe, fragmented atonality and baffling formal juxtapositions so redolent of its period.

The idea of intertwining female voice and solo violin that is a central feature of the new work – a half-hour setting, with large ensemble, of the "outsider" Italian, early-20th-century poet Dino Campana – is a promising one. But La Passione, completed this year, did too little of real interest with this conceit, and neither the work's undistinguished melodic material nor the semaphore gesturing and indistinct articulation of Cristina Zavalloni, the vocal soloist, helped to prevent one coming to the conclusion that Andriessen has, at least temporarily, rather lost his way.

Even the final night of the first three here under review was dominated not by any of the best expressions of Andriessen's mature manner, but by the Bang on a Can All-Stars' hour-long interpretation of Terry Riley's In C, the famous minimalist masterpiece. It was thus left to the festival's second phase to fill out some of the core of this fascinating composer's output.

The festival runs to 17 October (020-7960 4242)