[The Muses] in Pieria did Mnemosyne (Memory), who reigns over the hills of Eleuther, bear of union with the father [Zeus], son of Cronos, a forgetting of ills and a rest from sorrow. [...] she bare nine daughters [...] Cleio and Euterpe, Thaleia, Melpomene and Terpsichore, and Erato and Polyhymnia and Urania and Calliope [...]