Though highly regarded in his adoptive German homeland, the Argentinian-born Mauricio Kagel remains an indistinct figure in Britain.

Compared with his contemporaries, Boulez, Stockhausen, and Berio, his music is little heard here - partly because it fits uneasily into mixed programmes of contemporary works, but mainly, one suspects, because its witty subversiveness, its perceptive, critical commentaries upon the mores of performance and commercialism, are uneasily received; audiences just do not know what to make of him.

Yet the blast of fresh, undogmatic air that Kagel's arrival in Europe sent through the avant garde in the late 50s was a necessary corrective; the course of music in the last 40 years would have been very different without him.

It is also difficult music to bring off in performance, but the London Sinfonietta's all-Kagel programme last night (the first part of a two-concert homage this autumn) was exemplary. The air of anarchic theatricality has to be caught just right, but at the same time there is a sharp aural imagination at work under the playful surfaces. Even in Match, from 1965, a contest for two competing cellists (Anssi Karttunen and Sally Pendlebury) refereed by an increasingly impotent percussionist (David Hockings), the sounds are prescribed with absolute precision and enormous subtlety.

In Fürst Igor, Strawinsky, composed in 1982 to mark the 10th anniversary of the composer's death, a setting for baritone of the text of an aria from Borodin's Prince Igor acquires a disquieting dramatic component: Kagel's expressionist treatment is supported by broken-backed melodies from a raggle-taggle quintet of strings, percussion and brass, with punctuations from a second percussionist hidden behind a screen, who emerges in the final bars to propel the piece studiously into silence.

Sometimes the music does not quite sustain the ideas; Fürst Igor, Strawinsky goes on a fraction too long, and at more than 45 minutes Kantrimiusik's critique of folk musics and their commercial bastardisation stretches a charmingly witty idea too thinly. You get the point of this 1975 piece very soon: Kagel's sly caricatures of threadbare folk styles are effortlessly adroit, vocal interludes provide a well judged contrast, and the taped collages (chaffinches singing over a chorale, howling wind reducing the instruments to silence) add another layer of satire.

But without the theatrical presentation, you are left admiring Kagel's cleverness; as pure music