CLASSICAL MUSIC; FIDELIO: Bregenz Festival, CARMINA QUARTET: Kyburg Festival, 100th ANNIVERSARY PROM: Royal Albert Hall
THEY call Lake Constance the soul of Europe - and a few other things besides, because in true European spirit the countries that fringe this expanse of water have never been able to agree a name for it. By whatever name, the lake is a conspicuous meeting place of European cultures. At the moment, its most conspicuous feature is an awesome structure on an islet off Bregenz: something between a ski slope and a ferry terminal with a Cardiff backstreet at the bottom. It is the set for the Bregenz Festival's Fidelio, a prime piece of open-air spectacle opera playing to 6,600 people a night. The voices are amplified and the acting area so vast that the director's chief task is to fill it at all costs (currently topping pounds 10m).

But this is Austria, not Italy, and what you get at Bregenz is thinking- man's spectacle: grandeur with ideas, as opposed to the never-mind-the- quality- just-count-the-chorus tendencies of Verona and the Caracalla Baths. The Fidelio is the work of the old ENO team, director David Pountney and designer Stefanos Lazaridis, and they rationalise the stage-filling requirement by deciding that Fidelio is about the world ignoring evil in its midst - which gives them an excuse to fabricate a "world". It plays like TV soap-opera, against the backdrop of that life-sized Cardiff street where families of supernumeraries wash their cars, tend their gardens, make barbecues and otherwise lead their lives in disregard of the prison (covered by a sky cloth) that rears up behind them. The supreme coup comes when the cloth is removed, the houses disappear into the ground, and the prisoners are revealed stacked one above the other in glaring white solitary-confinement cells: a staggering effect, like nothing I have ever seen before on any opera stage. The audience cheers - the sheer feat of technology is irresistible. There is more of the same to come, including Florestan's cell floating through the darkness on a crane-arm and Pizarro governing the prison from a glass control-tower high up in the sky.

The problem is that Pountney gets carried away by the extravagance of it all. He plays the liberation scene cynically, as a media event with the ministerarriving by motor launch and surrounded by cameras. Then comes a carnival float swathed in the tricolour and carrying dancing girls, while the words "Liberte, Fraternite, Equalite" light up in a blaze of fireworks across the set. It's fun - and, heaven knows, Fidelio is dour enough most of the time - but vulgar. It has drawn the wrath of the Austro-German press. Beethoven, apparently, is turning in his grave.

Individual performances are overwhelmed by the staging. And musically ... well, it's better than I expected. The amplification system is sophisticated, feeding the sound through 40-odd speakers hidden around the set so that the voices "move" with their owners' bodies - so you get a sense of directionality and, up to a point, of quality. Susan Anthony's Leonore and Richard Paul Fink's Pizarro are both striking. The speakers are less kind to the orchestra, the Vienna Symphony, which plays hidden from view within the set. But given the circumstances, with no eye contact between the conductor, Ulf Schirmer, and the onstage singers, the co-ordination is miraculous. And, yes, it does somehow manage to produce moments of genuine musicality. This Fidelio is from start to finish memorable: not always for the right reasons, but for enough of them to outweigh the wrong ones.

The natural route to Bregenz for British visitors is a flight to Zurich and then a train which passes the Swiss town of Winterthur, host to a decidedly different kind of festival. Devoted to chamber music, it happens in and around the hilltop castle of Kyburg, an idyllic venue. The real draw of this festival is that it's the home-town project of the Carmina Quartet, one of the most distinctive and remarkable recent arrivals in the universe of European chamber music. Its recordings (on Denon) have been feted, not least its disc of Szymanowski quartets which won a Gramophone Award, but to hear it on home ground is a special experience. The Carmina wasn't all I heard at Kyburg - there were atmospherically charged performances by the Chilingirian Quartet, the countertenor Derek Lee-Ragin, and the Italian baroque band Europa Galant - but it stood out. Especially its account, one to a part with added double-bass, of Mozart's Eine Kleine Nachtmusik: standard repertory played in a strikingly unstandard way.

What gives the Carmina its particular sound is that the driving force comes from both ends of the en- semble: from the cello upwards as well as the first vio- lin downwards. There are times when Stephan Goer- ner, the immensely characterful cellist in question, takes a clear lead - as he does in the organisation of the whole festival, which runs with a typically Swiss mixture of charm and efficiency. Now in its fourth year, Kyburg is still developing; but as the reputation of the Carmina grows, I predict that it will soon be jostling for position with the cream of chamber-music fixtures.

In London, the 100th anniversary of the first Prom was marked on Thursday with a concert that wasn't all it might have been. The idea was a partial reconstruction of the first ever programme, using the New Queens Hall Orchestra, which plays on instruments from around 1900; and all it proved was how kitsch concert planning could be then. We were spared Eckert's Swiss Yodelling Song, and the "Chromatic Concert Valses from the Opera Eulenspiegel" by Cyrill Kistler. But with a second half that comprised Ambroise Thomas's overture Mignon, Schubert's Unfinished Symphony, "Largo al factotum" from The Barber of Seville and Bizet's Carmen Suite No 1, you realised what a shapeless rag-bag the Proms once were. It's a pity the centenary night wasn't observed with a more substantial celebration of what they have become.