The Critics: Classical: I'm a big fan of banned music. So let's ban lots more of it

Index on Censorship Concert: An Evening of Banned Music Union Chapel, N1 St Ceciliatide Festival Stationers' Hall, EC4 Christoph von Dohnanyi/ Philharmonia Orchestra: 'Wozzeck' Royal Festival Hall, SE1

There was a time when the north London liberal intelligentsia wore tweed jackets, dodgy shoes, and hand- knitted their own ties, if they had any. Now they come with dark, sharp business suits like lawyers (which they probably are) and the ability to pay pounds 150 for a ticket to the "Evening of Banned Music" which ran at the Union Chapel, Islington on Monday and was so awash with dark, sharp suits it might have been an extra-mural session of a senatorial impeachment council.

As a long-standing enthusiast for Banned Music - let's have more of it, I say, starting with Philip Glass - I naturally went along. I was behind the times in tweed, but impressed by the artists involved and the prospect of Messiaen's Quartet for the End of Time, with players of a calibre beyond the dreams of the composer when he wrote the piece in 1941. At that point, Messiaen was a prisoner of war in Silesia, and his quartet was scored for the random instruments available: violin, piano, cello, clarinet. Messiaen himself took the piano part; the rest were taken by fellow-prisoners.

On Monday night in Islington the violinist was Tasmin Little, the cellist Lynn Harrell and the clarinettist Antony Pay. And the pianist was no less than Simon Rattle, making his first public appearance since he left the CBSO in the summer. For good measure, he also accompanied the soprano Jill Gomez in songs by Poulenc, and compered a gala-roll of other performances by Robert Lloyd, Philip Langridge, David Owen Norris, and the demon pianola player Rex Lawson.

Now these are all fine (or at least, endearing) artists; and that they gave their time to support what is (north London jokes aside) a valuable campaign for freedom of expression was generous. But the fact remains that, with the exception of Lynn Harrell's flowering tone in the Messiaen, the performances were disappointing. Rattle, bless his heart, is no pianist. And for all its good intentions, this whole evening was so geared to making a polemical point that it brushed with dishonesty, beginning with basic matters of nomenclature.

Almost nothing in this "Evening of Banned Music" qualified for entry. Sure, the music was written in difficult circumstances, like world wars. But banned? No. And when Index on Censorship claims, as it does, that music is the art form most susceptible to proscription, that just isn't true. Music usually gets off rather lightly, because its language is too abstractly erudite to present much of a threat to people in power. The problem comes when you attach words to a score. In the realms of song and opera, censorship certainly has been a force to reckon with - think of Verdi - but words are the issue here, not music.

Having said that, I of course admit that there have been specific and significant examples of purely musical censorship in modern times, courtesy of Hitler and Stalin. And there's a pernicious species of constructive censorship creeping through the corridors of power in this country at this moment, damning everything that smacks of serious, high culture as "elitist". But to find banishment lurking in every corner, as Index on Censorship seems to, ultimately blurs the distinction between prejudice and judgement.

Music gets pushed to one side for many reasons: sometimes because it's simply no good. It has been judged by current standards of taste and quality, and failed. And though artistic judgements throughout history come riddled with mistakes, it's essential that someone somewhere at least tries to set a standard; otherwise every hack in Christendom would be demanding, as a right, a platform at the Barbican, the South Bank and the BBC.

In fact, some already do. Outside the Union Chapel on Monday was a man distributing leaflets that declared him a victim of banishment. He turned out to be the disgruntled composer who, back in the summer, sabotaged Simon Rattle's late-night Prom by letting off rape alarms. I'm surprised our old friends the Hecklers didn't show as well, since they constantly complain that their music is banned for being tonal. A more accurate assessment would be that it's ignored for being technically incompetent, derivative and opportunist. There's a difference.

One composer who was genuinely silenced by the censors - and excommunicated into the bargain - was Hildegard of Bingen. That extraordinary polymath religious has, in the year of the 900th anniversary of her birth, come into her own with CD sales that Pavarotti would find perfectly acceptable. But even in the 12th century she was something of an international celebrity: the confidant of kings and princes, and so daunting a scourge of the church authorities that, at one point, her entire convent was denied the sacrament and forbidden to sing the offices - most of which would have been set to chants by Hildegard herself. In response, she fired off heartfelt letters arguing that music gave essential voice to the relationship between mankind and God.

For that reason alone, she was the worthy subject of a special tribute in this year's St Ceciliatide Festival: an event which, three centuries ago, was an annual fixture at London's Stationers' Hall, and has now been revived in the very same place. Cecilia is, of course, the patron saint of music: her feast day is today. And it's curious that, with a female saint and with Hildegard as the first documented composer, the creative process of music should have turned out to be so male-dominated. I've no answers to that one.

But I do thrill to the elasticated beauty of Hildegard's melodic lines, which sounded surprisingly well at Stationers' Hall on Wednesday - sung by a small ensemble of women's voices (it has to be women) with the medieval accompaniment of rebecs, vielle and symphonia. The music came as part of a dramatised package devised by Kate Brown to illustrate the breadth and brilliance of Hildegard's interests - which extended beyond music and mysticism to cooking and cures for baldness. And it was fascinating. Whatever modern medical commentators do to downgrade her visions as by- products of migraine, Hildegard's enduring stature is assured. And 900 years on she has plenty, still, to say.

Last week I wrote a Worried-of-Hampstead paragraph about the appointment of Kurt Masur to chief conductorship of the LPO, concerned that his conservative outlook would anchor the orchestra in core repertory. But perhaps, from the broader viewpoint of South Bank policy, that's exactly why he's been chosen. There's another orchestra at South Bank, the Philharmonia, with another conductor, Christoph von Dohnanyi, whose heart beats in the 20th century and who thrives on the challenge of "difficult" works - especially works grounded in the methodology of serialism. Last weekend he was in his element with a concert account of Alban Berg's Wozzeck that came close to perfection.

It was all there: human pathos caught in the cold-steel grip of an objectivity that only melts in the last orchestral interlude, and a choking sense of enclosure slowly tightening around the necks of the main characters. It played in an unbroken sweep, without interval, and with a superb cast led by the bruised, animal hurt of Franz Hawlata's Wozzeck and the sacrificial strength of Deborah Polaski's Marie. Graham Clark and Eric Halfvarson were wonderfuly horrible as Wozzeck's tormentors, the Captain and the Doctor.

And there was spendthrift luxury in booking Ian Bostridge as the Fool - who only sings 10 words but has to make them count. As an accomplished lieder artist, Bostridge knows exactly how to do that. And there's no word in the text that matters more than when the Fool sings "Blut!" Here, it was devastating. Worth the journey for that syllable alone.