Ahead of his Sibelius cycle with the Adelaide Symphony Orchestra, Chief Conductor Mark Wigglesworth talks with Jansson J. Antmann about the composer’s radical reinvention of the symphony and enduring legacy.

Jean Sibelius between 1940 and 1945 at his home Ainola in Finland. Photo © PD Archive/Alamy

Imagine you’re in Finland. You walk along the waterfront path that traces the edge of Taivallahti Bay, where the marina opens out towards the broader Seurasaarenselkä basin and the Baltic Sea. It is early autumn in Helsinki; the air is sharp, and the silver birches and aspens in Sibelius Park have turned a shade of gold. The path bends inland, and in the clearing ahead, something catches the fading light. At dusk, it almost seems to glow,...