The speaker addresses someone absent or dead, a thing, a place, or an idea, as if they could hear.
In the Iliad
sing, goddess, of the wrath of Achilles, son of Peleus, the baneful wrath that brought the Achaeans countless griefs.
The narrator addresses an absent goddess with the imperative "sing, goddess," as if she could hear him. The request places the story under the authority of the one who knows it and gives the poet the position of one who only repeats what he receives.
Book I: The Plague and the Wrath, the narrator
Tell me now, Muses who have Olympian homes, for you are goddesses, you are present and know all things, while we only hear the fame and know nothing.
Book II: The Dream and the Catalog of the Ships, the narrator
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