The first name on the programme, Aaron Copland, ought to have been the exception. The Copland of Rodeo, Appalachian Spring and other American folksy creations has long been a favourite target for nostalgia-hating progressives but the acerbic, rhythmically complex Short Symphony (in Dennis Russell Davies' reduced scoring) has a sharp edge and a concentrated inventiveness that few of his later works match. Put some rather more recent star American composers beside this - Michael Torke for instance - and you wonder what they have to add. The Short Symphony has all Torke's rhythmic and colouristic brilliance, but it also has a subtle sense of line, superficially fragmented, but essentially taut that a lot of recent rhythm-preoccupied American music lacks.
In the Short Symphony, the London Sinfonietta sounded as though they could have done with at least one more rehearsal - there was a cautiousness at odds with the forward- thrusting spirit of the music. But in Webern's Concerto, Opus 24 they were utterly at home. This was a beautiful performance: highly expressive and lucid at every level. When the music is performed like this, its clarity of thought becomes almost luminous. Following the patterns and their mirror images is simplicity itself. One wonders why so few of Webern's followers were prepared to learn from that, opting instead for self-obscuring perplexity - unless it was simply that they never heard Webern played so well.
'Lucid' may not be the word that leaps to mind during Edgard Varese's Ecuatorial, and yet the writing is obviously as he heard it - Varese knew the sounds he was creating and there's a gripping sense of cohesion. Bass Stephen Richardson was not, unfortunately, as powerful a presence as the Sinfonietta's brass, percussion and keyboard. His rendering of the elemental Spanish texts sounded very English. Flautist Sebastian Bell's performance of the tiny solo piece Density 21.5 was much more stylish. This is a pioneering piece, but whether the music itself merits the totemic significance it has acquired in the avant-garde 1960s and 1970s is an open question.
John Cage's First Construction (in metal) suggested strongly that when it came to Sixties modernism, Cage had seen it all. The material is essentially simple but infectious, and the sounds, including a gong lowered into a tub of water, are wonderful - could this really be a Thirties piece?
Rather more enigmatic was Schoenberg's Chamber Symphony No 2 - ideas from before the First World War reworked just before the Second. The veering from just-tonal, very late romanticism to writing more reminiscent of the later, academic serialist, is disconcerting. The programme notes suggested that the dark E flat minor coda mirrored feelings in the last days before the Second World War, but it could have easily have been the end of Franz Josef II's Vienna that the music was mourning.
That's the problem with this kind of art / age programming: the parallels between a work and its time can be interesting, but you can push them too hard; there's more to music than historical newsreel. But it was good to have an excuse to play the Second Chamber Symphony, and to hear it performed with such conviction.