Australia has many fine exports – wine, women, gap year anecdotes – but increasingly it is her orchestras that are setting the standard. With a magnificent Proms performance from the Australian Youth Orchestra still fresh in the ears (as well as a significantly reinvigorated Sydney Symphony courtesy of Ashkenazy), last night it was the turn of the smaller and still-deadlier Australian Chamber Orchestra to fly the national flag, in what may well prove to be the finest concert of the summer.

Boy, did I want to enjoy this Prom. On paper it should have been the highlight of the season. Young Canadian conductor Yannick Nézet-Séguin has been making his mark in London as principal guest conductor of the London Philharmonic Orchestra with several sensational performances of Bruckner over the past few years. Here he was for his Proms debut at the helm of his smart new orchestra, the Rotterdam Philharmonic (Gergiev's old outfit).

If the bust of Sir Henry Wood that watches over the stage of the Royal Albert Hall had come to life, Commendatore-like, during last night’s concert, I can’t help feel that he would have been smiling. Beethoven nights – once a popular Proms fixture – have lately fallen off the calendar, but alongside various nods to tradition have this year returned. Following Jiří Bělohlávek and Paul Lewis’s recent concerto-fest, Paavo Järvi and the Deutsche Kammerphilharmonie Bremen last night presented a second all-Beethoven programme.

For the couch-bound classical music lover, keeping up with the Proms is pretty straightforward. Step one: open bottle of agreeable claret. Step two: turn on Radio 3 and listen, or watch selected Proms on BBC Two or BBC Four. Or, indeed, catch up on the iPlayer. But needless to say, there's a colossal amount of work going on behind the scenes to make it all happen.

Two pianists, one indisputably great and the other probably destined to become so, lined up last night to show us why the Proms at its best is a true festival, not just a gaggle of summer concerts. First there was the prince of pearly classicism, Paul Lewis, consolidating the democratic Beethoven he’s already established on CD withJiří Bělohlávek and the BBC Symphony Orchestra. Then along came the queen of romantic night, Maria João Pires, to unfold a late-night brace of Chopin nocturnes.

Hans van Manen does basic instincts in ballet better than anyone alive. The Dutch choreographer, nearly 78 and far too little exposed in Britain, is a near-contemporary of Kenneth MacMillan, another specialist in sexual relations, but where MacMillan is fascinatingly drenched in guilt, Van Manen takes a bold, guilt-free stand. Grosse Fuge, which Birmingham Royal Ballet revived in the Hippodrome last night in a smart triple bill to entertain all tastes, is all about mating display - four men in black oriental skirts and big-buckled belts, four women in beige Playtex-type corsets that give them mumsy boobs and look unusually sexy.

To launch a music festival with the Arditti Quartet, as Bath has just almost done (a pair of dance events preceded them), is a bold enough gesture, if no bolder than for the Arditti to open up their Assembly Rooms concert with Beethoven’s Grosse Fuge – a finisher if ever there was one. But for this particular group, late Beethoven might well seem like a kind of starting point. Beethoven was the first to write unplayable music for string quartet; and the Arditti have always specialised in the unplayable.

It's still not clear whether his clever, brilliantly orchestrated compositions are here to stay (though they're certainly having a good run at the moment). As a conductor, he's not yet nimble on his feet. Yet after yesterday evening's colossal recital, I doubt if anyone would deny that Thomas Adès is a pianist of the first order, a dramatic master of keyboard colour who pulls you into his edgy but often very beautiful sound world and sometimes casts you adrift from your critical moorings.