MUSEUS, an ancient Greek poet, was, according to Plato and Diodorus Siculus, an Athenian, the son of Orpheus, and chief of the Eleusinian mysteries instituted at Athens in honour of Ceres. According to others, he was only the disciple of Orpheus, though, from the great resemblance between his character and talents and those of his master, he was called his son, as those were styled the children of Apollo who cultivated the arts of which he was the tutelar god. Musaeus is allowed to have been one of the first poets who versified the oracles. He is placed in the Arundelian marbles, in epoch fifteen, 1426 n. c. at Mea, which time his hymns are there said to have been received in the celebration of the Eleusinian mysteries. Laertius tells us, that Museus not only composed a theogony, but formed a sphere for the use of his companions; yet as this honour is generally given to Chiron, it is more natural to suppose, with Sir Isaac Newton, that, after the conquest of the golden fleece, he enlarged it with the addition of several constellations. The sphere itself shows that it was delineated after the Argonautic expedition, which is described in the asterisms, together with several other more ancient histories of the Greeks. Museus is celebrated by Virgil in the character of hierophant, or priest of Ceres, at the head of those illustrious mortals who had merited a place in Elysium.

A hill near the citadel of Athens was called Museum, according to Pausanias, from Museus, who used to retire thither to meditate and compose his religious hymns, and in which place, also, the poet was afterwards buried. The works which went under his name, like those of Orpheus, were by many attributed to Onomacritus. Nothing now remains of this poet, nor were any of his writings extant in the time of Pausanias, except a hymn to Ceres, which he made for the Lyconides; and as these hymns were likewise set to music, and sung in the mysteries by Museus himself in the character of priest, he thence perhaps acquired the title of musician, as well as of poet, the performance of sacred music being probably at first confined to the priesthood in these celebrations, as it had before been in Egypt, where they originated. He, however, is not enumerated by Plutarch amongst the ancient musicians; nor does it appear that he merited the title of son and successor to Orpheus so much on account of musical abilities, as of his poetry, piety, and profound knowledge in religious mysteries.