TRANSIT is a festival packed into just a weekend. Despite this, it consistently punches above its weight in international standards of performance and a commitment to today's most adventurous music; this year's festival featured 18 premieres. It is one of the most attractive autumn European festivals, based in the Flemish town of Leuven, though the sheer number of events leaves little time for sightseeing.

Let us imagine we are approaching the shore of an unknown island, taking part in an expedition. With great surprise, we recognise that the island is inhabited. Strange-looking but seemingly friendly people step out of the woods; they wave to us and invite us to take part in a big celebration. A ritual is being performed in our honour with exotic music played on exotic instruments. The unfamiliar sounds accompany a narrative that we cannot fully grasp. Two men are fighting; the winner spares the life of the loser. Then, in Act Two, a woman enters the scene: she seems to have lost a goat from her herd, she argues with a guy who is deaf and cannot help her; all of a sudden there is a big party going on and everyone is cheering happily. We are left stunned by the mysterious performance, by its energy and physicality, by the impact of its sounds and rhythms.

For this Norwegian music critic, visiting a German music festival always means excitement and great expectations for, given its long traditions and proud institutions, German musical life has a special attraction. However, the reality may sometimes be quite astonishing. So it was that after about an hour on the train from Düsseldorf Airport, climbing down the steps at Witten Hauptbahnhof, I couldn't help asking myself, ‘How can it be that this rather anonymous-looking little town will, for the coming couple of days, be the centre of the relatively narrow field of contemporary chamber music?’.

The Amsterdam contemporary music scene has long been known for its open-mindedness and willingness to explore, and any given evening can be a toss-up between electronic clog dance (served with soup) or piano-playing dogs. A petri dish of creativity, this is given a podium and a voice by the Muziekgebouw aan 't IJ. This edifice of concrete and glass, moored like an industrial spaceship on the banks of the river IJ, is branded in English as the ‘Concert Hall of the twenty-first century’, and indeed their flavourful mix of programming celebrates the more unusual sides of classical music, from the very old to the very new, from Gesualdo consorts to dirty electronics.

I've known Claude Vivier's marvellous chamber opera Kopernikus for more than ten years, have seen several productions, have studied the music in detail, have written about it. But what, sacré nom de Dieu, is it actually about? There is something elusive, ungraspable, about this féerie mystique, as Vivier called it (a mystical enchantment). Ostensibly, Kopernikus tells of a woman's journey to the next world. But there is no real narrative as such, and a great many detours and off-ramps, such that an audience could be forgiven for not grasping this central fact. What the work is not about – appearances to the contrary – is the Renaissance astronomer Nicolaus Copernicus, who barely features in the opera, only appearing at the end to open the gates of heaven. Vivier explained that it was the mythic Copernicus that interested him, ‘the idea of the cosmic searcher’, and that he had made no attempt to research the life and thought of the real Nicolaus Copernicus. The principal character is Agni, the Hindu deity – a male god, but represented here in female form by an alto. Vivier made it clear that he identified strongly with the central character, so much so that we may regard Agni as one of the long list of ‘Vivier characters’ in his work. In a press release at the time of the work's premiere he noted: ‘Agni is the Hindu god of fire ... Fire is my astrological sign. I was born on April 14. I am Aries, the ram. Agni, c'est moi’.