Polyhymnia was born among the nine Muses, daughters of Zeus and Mnemosyne. Hesiod places her seventh in the sequence Clio, Euterpe, Thalia, Melpomene, Terpsichore, Erato, Polyhymnia, Urania and Calliope. Her name was later interpreted as 'many hymns', and later writers and artists made sacred hymnody one of her principal spheres. The pensive, veiled figure familiar from Greco-Roman art belongs to that later iconographic tradition.

Hymns accompanied many Greek sacrifices, processions and festivals, but there was no rule that every Greek ritual everywhere began with one identical type of hymn. Greek religious song included paeans, processional songs, invocations and other forms suited to particular gods and occasions. Polyhymnia's later domain gathers these solemn acts of praise under a single Muse rather than documenting a personal role for her in every rite.

The hymn kept time with the whole of Greek life, and her name, many hymns, is a list of occasions. Before battle the soldiers sang the paean, the hymn to Apollo that steadied the spear-arm and called the god's arrows down on the enemy; the word paean itself became so tied to the cry that a wounded man gasping for help was said to call the god by it. When a Greek city sent out colonists to found a daughter city across the sea, the departing ships carried fire from the mother city's hearth and a hymn on the sailors' lips, for the gods who protected the old ground had to be praised before the new. At funerals the mourners sang the threnos, the dirge of the dead, and at the threshing floors the harvesters sang their hymns to Demeter between the rows of wheat. The hymn was thus the most public of all songs and the most constant: comedy came once a year, the ode for a champion came once a lifetime, but the hymn came every week of every life, and the Muse who kept it had to be the steadiest of the nine. That is why the artists gave her the veil and the thoughtful finger: she is the Muse of repetition that never grows stale, of words worn smooth by ten thousand voices, of the praise that has been said before and must be said again.

The famous contest between the Muses and the daughters of Pierus belongs to the mythology of the Muses as a group. Ovid does not give Polyhymnia a special silent or gestural performance in that contest. Her association with contemplative pose and grave gesture comes instead from later artistic representation, where she is often shown wrapped in a cloak, resting against a support or appearing absorbed in thought.

The later Orphic Hymns show how important formal sacred song remained in Greco-Roman religion, but the surviving collection is not a book personally attributed to Polyhymnia. Its relevance is thematic: a Muse later assigned sacred hymnody naturally became an emblem for the kind of repeated ritual praise that these hymns preserve.

Rome took her over with the rest of the nine and found her the easiest to keep, for every people sings to its gods. Roman ceremony had always been heavy with fixed words, prayers whose exact form was guarded by the priesthoods, and the Roman mind, practical and legal, took naturally to a Muse whose art was the correct repetition of praise. In the great houses her veiled figure presided over the quieter rooms, and the artists of the empire carved her again and again in her thoughtful pose. The philosophers who catalogued the Muses in later centuries tried to widen her domain, giving her eloquence and rhetoric, and in the Renaissance the handbook-writers of symbols went further and seated her with compass and globe as the Muse of geometry, which was their way of saying that her silent meditation belonged to every serious study, not only to song. But her true conquest was the word hymnos itself. The Christians of the early centuries had no objection to the hymn, only to its gods, and they filled their services with songs in the old forms; by the fourth century the Latin churches of the West were singing newly made hymns every week, and the Greek word passed through Latin into every tongue of Europe. Today half her name sits in every hymnbook on every pew, sung weekly by millions who have never heard of the Muses, and the joke would have pleased her: the goddess of many hymns ended with the most many of all flocks.

She circles still. In October of 1854 the French astronomer Jean Chacornac, working at the Paris Observatory, discovered a small planet of the belt between Mars and Jupiter and named it 33 Polyhymnia, adding the veiled Muse to the growing congress of her sisters among the stars, where 18 Melpomene, 23 Thalia, 27 Euterpe, 62 Erato, and 81 Terpsikore already wandered. The word she keeps has proved harder to kill than the religion that first sang it: hymnbooks are still printed, choirs still rehearse on winter nights, and nations still sing. Her image in art became the very emblem of meditation itself, the veiled woman with a finger to her lips, so that centuries of painters borrowed her pose for sibyls, prophets, and allegories of thought without ever needing her name. And her tradition runs in every voice raised together, in school assemblies and stadium anthems and midnight services, wherever people who cannot see what they praise sing anyway, because singing is the shape praise takes. From the processions of Delos to the hymnals of the present day, Polyhymnia remains She of Many Hymns, the proof that silence, wrapped around a song, is the deepest praise of all.