As with Das Rheingold and Die Walküre, Barrie Kosky’s thrilling new Siegfried has its feet planted firmly in the natural world. However, this third instalment feels different. A lightness of touch in both Kosky’s direction and conductor Antonio Pappano’s supple way with the score allows an irresistible sense of joy to creep into Wagner’s tetralogy.

Presiding over it all is the Earth goddess, Erda, portrayed with magnetic presence by Illona Linthwaite. A frail old woman, she appears both vulnerable in her nakedness and yet strangely comforting as she watches over Siegfried, himself a child of nature.

Andreas Schager as Siegfried, Royal Opera House, London. Photo © Monika Rittershaus

Set designer Rufus Didwiszus’s charred trees may have been inspired by the devastation of Australian bushfires, but here Kosky signals a change of mood. As the curtain rises, we see Erda’s feet dangling in mid-air before the rest of her appears lazily rocking herself on a swing.

In this make-believe world, Mime and his foster child inhabit a tiny treehouse. The grizzle-haired dwarf appears...