Donner

Donner waits almost the whole of Das Rheingold to do one thing. The Ring's prologue belongs to Wotan, to gold and curse and bargain — and then, at the end, the air must be cleared so the gods can cross into Valhalla. That work is given to the god of thunder, and it is the role's whole reason to exist.

He gathers the storm and strikes — "Heda! Heda! Hedo!" — and the hammer falls. Lightning, thunder, and from the cleared sky Froh's rainbow bridge. Like Orest, Donner is a short part that the evening has been waiting for: one summons, one blow, and the weather answers.

The voice has to be the storm before the storm arrives. It sits low and broad, German consonants cut like flint, and the call must ride over the full orchestra without forcing — not a shout but a command the sky obeys. You sing the lightning, then let the hammer do the rest.