The rebel who lost his cause; MUSIC

Philharmonia Festival Hall, London;

Philharmonia

Festival Hall, London

The 's 50th anniversary party is underway. This week's concerts were unapologetically insular - "made in Britain", every last note - apart from Leonard Slatkin, that is, who flew in from the new world to the old country to host them. Who better? Sometimes it takes an outsider fully to appreciate the vitality of our own musical heritage. Slatkin has long since earned the title of "honorary Brit".

The oldest of the music was marginally older than the orchestra, the newest barely dry on the page. And for once Sir William Walton was honoured guest and not gate-crasher. It's not often that both his symphonies get programmed. Indeed, the scarcity of the Second is such that it might almost have never existed. In the 20 years that separate them, Walton had graduated from angry young man - the renegade force in British musical life - to benign reclusive. To hear both symphonies in relatively close proximity is to understand what happened. Italy happened. And he grew up. He never lost his sharp tongue - the juxtaposition of the cynical and the sensuous is one of his music's most striking characteristics - but, to some extent, the rebel lost his cause.

The Second Symphony was probably quite an exotic species back in 1960. The hothouse variety, textures shot through with the shimmer of vibraphone, celests, harps. It's real Mediterranean twilight, haunted end of day stuff, its phantasmic, vaguely sinister character radiating outwards from the central Lento assai. Not for nothing did sognando ("dreamy") become Walton's favourite expressive term. The sinewy cantabile which winds its way through this intriguing slow movement is the very heart of the matter. But for the rest, the gestures lack motivation. Even Slatkin could not persuade me that the treacherous fugato of the finale (and even the could not disguise some momentary desperation here) was anything other than a composerly "last resort". The high-gothic 12-note theme at the start of the finale (replete with baroque trills) is a striking basis for something, but not that. What an anti-climax.

No such thing as anti-climax in the First Symphony. Now the fugato in that belated finale arrives with roaring inevitability out of all that has gone before. And the audacity of all that has gone before can still brow-beat an audience into submission. This is Walton's coming-out, the scars of youthful endeavour proudly flaunted in every over-zealous tutti. Slatkin and the orchestra delivered a cracker of a performance, lethal in its rhythmic acerbity (timpanist Andrew Smith taking no prisoners) and the primitivism of its colours, like that terrifying exchange of gravelly lowstopped horns and tuba leading on the grim processional to the first movement coda.

So what of today's angry young men? Well, both James MacMillan - represented here by Veni, Veni, Emmanuel, his highly theatrical percussion-led journey from Advent to Easter - and Michael Berkeley are well beyond that stage, though Berkeley has been displaying worrying signs of musical hypertension just lately.

His Viola Concerto, here receiving its London premiere, struck me as a curious mismatch of genre and instrument. From an opening statement of genuine curiosity and promise, played out against the expectant chiming of bells, this most expressive, but vulnerable, of instruments is plunged into an orchestral maelstrom of such high density and anxiety that it fails to reach the ears with any real degree of coherence - musical or otherwise.

All of which leaves the soloist (the highly accomplished Roger Benedict), not so much waving but drowning, forced repeatedly into his highest and least grateful register - more an act of survival than expression. Ironically, the viola variation in Britten's Variations and Fugue on a Theme of Purcell later served to remind me of a beauty and consonance that I know is in Berkeley's gift.