Polyhymnia is one of the nine Muses, the daughters of one mind whom Mnemosyne bore to Zeus in Pieria to be a singing memory of all that gods and mortals do. Hesiod's catalogue sets her name near the close of the roll of sisters who dwell on Olympus — Erato and Polyhymnia and Urania and Calliope, chiefest of them all; Pseudo-Apollodorus, reckoning the same sisterhood Memory bore to Zeus, places her last of the nine, spelling the name Polymnia. The two spellings — Polyhymnia in Hesiod, Polymnia in Apollodorus — name a single Muse.2Hesiod · Pseudo-Apollodorus — Theogony 75–79; Bibliotheca 1.3.1

Her name is built from the Greek for 'many' and 'hymn', and is read as 'of many hymns' or 'much singing'. In the earliest sources she has no separate office of her own: Hesiod and Pseudo-Apollodorus treat the Muses as a single chorus of song rather than dividing the arts among them. The familiar later assignment of Polyhymnia specifically to the sacred hymn — and, in other versions of the canon, to rhetoric, to mime, or even to agriculture — is a Roman-era systematization laid over the older undivided sisterhood, not an attribution found in the early Greek mythographers.3Hesiod · Pseudo-Apollodorus — Theogony 75–79; Bibliotheca 1.3.1

Around the Muses' very parentage the ancient authors diverge. Pausanias records a Boeotian tradition that Pierus, a Macedonian who gave his name to the mountain, came to Thespiae and established nine Muses, changing their names to the ones now used. This rival reckoning, in which the figures called Muses were renamed or even refathered by Pierus, stands against the older descent of Polyhymnia and her sisters from Zeus and Mnemosyne preserved by Hesiod and Pseudo-Apollodorus.4Pausanias — Description of Greece 9.29.3⚖Told differently in other tellings — change the lens on the card