Music: Elliott Carter

QEH, London

Once renowned for scores so structurally complex, so rich in surface detail that, in the 1960s, he was able to complete only three works, Elliott Carter, the grand old man of American music, has, in the past 12 years, written some two-dozen pieces, including several really meaty works and a surprising number of more modest, directly appealing ones. On Monday, the London Sinfonietta's almost year-early celebration of his 90th birthday included the most recent of the more substantial works: a Clarinet Concerto premiered last year in Paris. In an engagingly witty pre-concert discussion, Carter said that he began to wonder more than 20 years ago if he could "produce more easily the effects I had in mind", and disarmingly admitted that "I know what I like to hear now". "What he likes to hear" is, both texturally and structurally, now more readily grasped in outline at a single hearing. Mention of a proposed opera was, though, still rather a shock.

Yet as the 18-minute, seven-part structure of the new concerto made clear, leaner does not equal meaner. There's plenty in this new work to occupy the mind and engage the emotions in characteristic Carter style. The solo clarinet part - its almost unbroken line eloquently conveyed here by Michael Collins - leaps and frolics but has its tender, more lyrical moments, too. Around it, a procession of instrumental groups, formed from the 18- piece ensemble, changes from section to section: mallet instruments, harp and piano in the first section; unpitched percussion in the second; and so on. Tutti passages surround each of the first six sections and all 18 players join in the last one. On Monday, structural clarity was further enhanced by the clarinettist's movement between six different spots on stage, though this is not specified in the score. Predictability is avoided by introducing commentaries from instruments alien to the group involved, and by a variety of relationships between soloist and ensemble. I found the mainly slow third and fifth sections (the former with muted brass providing an almost archaic feel, the latter with some melting string counterpoint) especially compelling, and the work's final stages are appropriately cumulative.

In a typically well-planned programme, the concerto was preceded by short tributes by Witold Lutoslawski and Milton Babbitt written for Carter's 80th birthday and by Oliver Knussen's splendidly virile Coursing, dedicated to Carter on his 70th. It was followed, in the second half, by a rare performance of one of those infamously difficult 1960s compositions, the Double Concerto for Harpsichord and Piano with Two Chamber Orchestras (John Constable and Ian Brown were the accomplished soloists). Despite its complex metric modulations and superimpositions, this work's dangerous- to-know image was delightfully challenged by a performance of superb musicianship. Having the group of players attached to each soloist clearly separated on stage was a considerable aid to apprehending the structure. But it was surprising to note, too, just how texturally transparent, and how lyrical, this music can be. And how unforbidding, natural and direct it can seem, at least in the hands of a conductor like Knussen. At the end, Carter received a well-justified ovation from a near-capacity audience.