Magnus Lindberg Festival, South Bank Centre, London

With the exception of Sibelius, few Finnish composers can be said to be household names. The South Bank's attempt to establish Magnus Lindberg as such continued over last weekend with a modest event in the Purcell Room and a massive extravaganza in the Festival Hall next door . On Friday, the Arditti Quartet put Lindberg alongside Stravinsky and Berg. The composer's own performance of his Six Jubilees for piano was authoritative and powerful; Lindberg clearly has little trouble finding the notes (and there are often an awful lot of them – some might even say too many), but underneath this torrent there is always a strong sense of rigorous structure. The virtuosic Clarinet Quintet of 1992 was even more of a case in point. Kari Krikku performed prodigies on the clarinet and the Arditti brushed aside horrendous technical difficulties to bring off this extraordinary filigree of long, furiously interweaving lines, glissandi, harmonics and trills. A blessed solo clarinet interlude reminded us that sometimes less is more, before the curiously Greek-sounding final flourish.

The overall effect was certainly impressive, though in this case a cold, glittering surface predominated over any inner core of expression – always a danger for a composer who once said, "only the extreme is interesting".

What was interesting was to hear a masterly rendition of Berg's Lyric Quartet in close juxtaposition. There did seem to be a connection with Lindberg, not only in some of the sounds and textures, but in the sense that Berg was also obsessed with structural proliferation while wishing to retain a link with traditional musical expression.

In Sunday's Philharmonia concert, Esa-Pekka Salonen celebrated Finnish independence with Sibelius's huge Kullervo Symphony and the even huger Kraft by Lindberg. The decision to begin with Kullervo was an odd, and as it turned out, unwise one. The Philharmonia gave a scorching performance of this fearsome legendary tale of rape and suicide, and the Polytech Choir of Helsinki was in blood-curdlingly fine form vocally, as were the soloists Monica Groop and Jorma Hynninen. Sibelius here uses large forces in a relatively simply way to achieve a monumental effect.

The trouble with Lindberg's Kraft, written in 1985, is that it strains with gigantic forces for an effect that, in the end, turns out to be largely incidental. The various wanderings of orchestral players round the hall and the extraordinary antics of Lindberg and the rest of his performing group Toimii were more distracting than theatrical. And though there are some amazing sounds in the piece – particularly the gong resonances and twittering woodwind halfway through – the effect is of a series of exotic events, and a selection of "new music" gestures that are, frankly, old hat nowadays. The audience member hit by a collapsing tam-tam was luckily not seriously injured, but the incident, though presumably unplanned, was somehow characteristic of a piece that relied more on sensational effect than substance. In the case of Kraft, it seems that more is probably less.