The contrast is striking when, on the hottest day of the year, you step down from the green lawns of Søndermarken into the underground world of the Cisterns, Copenhagen’s old water reservoir. The humidity is high, the light sparse, and stalactites hang from the vaulted ceilings, casting shadows in the puddles on the floor. And then there is the sound: in the empty columned halls, the reverberation can last up to 17 seconds. Even the slightest scrape echoes down here.

Since 2016, the Cisterns have functioned as an exhibition space, and this year Jakob Kudsk Steensen has transformed the halls into an underwater landscape of video projections, sculptural objects, and a soundscape created by Lugh O’Neill featuring Bjarke Mogensen on accordion. Mogensen, who is performing this evening, has a versatile taste. Perhaps a bit too versatile, I think to myself as I read the evening’s program, which spans from Bach to folk melodies from Bornholm. It turns out to hold together better than one might expect. These are compositions that seem to stretch time itself, where long tones – amplified and extended by the reverberation – form a murky foundation for short, pearling attacks, like marble balls ricocheting off a stone wall.

A shimmering, sorrowful composition by Nick Martin, inspired by Michelangelo’s Pietà – marble again – is followed by a meditation on echo among the cliffs of Bornholm by Frederiksberg-based composer Martin Lohse. Another piece rises slender and sacred like high vaults, while Mogensen’s own Passage crackles, snaps, and crunches like stones being broken. Mogensen’s accordion is in constant dialogue with the space; he calls, and the dark colonnades answer back – or is it the other way around?

The audience sits petrified, completely absorbed in the sound, as Mogensen masterfully makes his instrument sound like everything from a rapid breath to a thunderclap. When we finally emerge, heavy clouds hang over Søndermarken, and the heat is gone. The park feels transformed. The contrast is tangible.

English translation: Andreo Michaelo Mielczarek