Einstein on the Beach was meant to be one of the jewels in the crown for the Cultural Olympiad. The celebrated 1970s collaboration between Philip Glass, Robert Wilson and Lucinda Childs - which Susan Sontag claimed to be one of the greatest theatrical experiences of the 20th century - was receiving its UK premiere at the Barbican Theatre last night, thirty-six years after it was first created. And what we got was a technical shambles.

Gerald Barry's new operatic adaptation of Wilde's The Importance of Being Earnest delivers a number of firsts. The first opera score to contain an ostinato for smashed plates. The first orchestra to include a part for pistols and wellington boots. The first opera (that I know of) to offer the role of an aging mother to a male bass. And the first opera I've been to where I've cried with laughter.

This has to be the only music festival I've ever been to where two vacuum cleaners were on standby in case the star performer conked out. But that's what happens when your star performer is a player piano - they seem to run on Hoover tubes. With 11 concerts and one film in two days, this celebration of American maverick Conlon Nancarrow was London's alternative marathon. One that was no less eccentric, exhausting or adrenalin-generating (though much less running-based).

Southbank Centre’s current season has included weekends devoted to three contemporary giants: Pierre Boulez, Conlon Nancarrow and George Benjamin. But it closes with a festival devoted to not to one contemporary composer but 20. The New Music 20x12 weekend, initiated by the PRS for Music Foundation, is a Olympic celebration of the range and diversity of new British composition. Indeed, the only thing all 20 pieces will have in common is that – you’ve guessed it - they will last 12 minutes.

I don't have many feelings about the Titanic (any more than I do about any tragedies of the distant past). I know few of the facts, I can remember nothing of the film and I have been left almost completely untouched by the centenary. Yet I am enormously grateful to have caught a Barbican performance of The Sinking of the Titanic, Gavin Bryars' beautiful musical meditation on the event.  

I find it hard to square what I know about composer Judith Weir with what happened last night. In one corner lies her 30-year output of songs, choral pieces and operas - as engaging and beguiling an oeuvre as that of any living composer's. I think of her waggish song cycle King Harald's Saga or her playful opera A Night at the Chinese Opera.

If you need music for a ceremonial occasion, Greek composer Vangelis is your man. He has, after all, even had a small planet named after him, and in 2001, NASA used his piece Mythodea as the theme for its Mars Odyssey mission. The following year, FIFA hired Vangelis to concoct the official anthem for the 2002 World Cup. In 2004, he draped aural grandiosity across Oliver Stone's implausible Alexander.  

It is unusual in art for collaborators to be of equal star-wattage. The pairing of Benjamin Britten and WH Auden was one such. Another, much longer-lasting, was Stravinsky and Balanchine, a partnership of equals that endured for nearly half a century. More recently, Antony Gormley has worked with both Akram Khan and Sidi Larbi Cherkaoui, to great effect. Can Turnage, McGregor and Wallinger replicate these? This has been the question.

Stockhausen’s Gesang der Jünglinge (Song of the Youths), composed in 1956, is, in many ways, the mother of all electronic music. I can remember discovering it in the 1960s, before I had acquired my first pair of Koss headphones, lying on the floor, strategically placed between two speakers, my ears opened by the copious ingestion of some red Lebanese. The combination of electronically treated live voices with purely synthetic sounds, so much a commonplace today, was then strikingly new.