And again, [Zeus] loved Mnemosyne

...with the beautiful hair: and of her the nine gold-crowned Muses were born who delight in feasts and the pleasures of song. Theogony, XII, 915

For it is through the Muses

...and Apollo that there are singers upon the earth and players upon the lyre; but kings are from Zeus. Happy is he whom the Muses love: sweet flows speech from his lips. Homeric Hymn XXV