He lives for moments like this. Teodor Currentzis stands on the balcony inside a museum in Perm, 900 miles east of Moscow, at the point where Europe merges into Asia. In pre-Soviet days the museum was a church, so 1,400-year-old icons loom over him in the flickering candlelight. Squashed together in front of him are 30 singers from his MusicAeterna choir. Packed behind him — squatting on the floor, crushed together on the stairs, even perched on exhibit cases — are hundreds of punters.

Whatever health-and-safety regulations cover regional Russian museums, they are being comprehensively flouted here. Nobody has advertised the event. Yet somehow, as with most of Currentzis’s spontaneous happenings, word has got out.

He loves that. The best thing about performing at the