Envious of Niobe, the wife of her husband's brother Amphion, who had six sons and six daughters, she formed the plan of killing the eldest of Niobe's sons, but by mistake slew her own son Itylus. Zeus relieved her grief by changing her into a nightingale, whose melancholy tunes are represented by the poet as Aëdon's lamentations about her child.
According to a later tradition preserved in Antoninus Liberalis, Aëdon is instead the wife of Polytechnos, an artist of Colophon. The couple boasted that they loved each other more than Hera and Zeus. Hera sent Eris to cause trouble between the two of them. Polytechnus was then making a chair, and Aëdon a piece of embroidery, and they agreed that whoever should finish the work first should receive from the other a female slave as the prize. Polytechnos was furious when Aëdon (with Hera's help) won. He went to Aëdon's father, and pretending that his wife wished to see her sister Chelidonis, he took her with him. On his way home he raped her, dressed her in slave's attire, commanded her to silence, and gave her to his wife as the promised prize. After some time Chelidonis, believing herself unobserved, lamented her own fate, but she was overheard by Aëdon, and the two sisters conspired against Polytechnus for revenge. They murdered Polytechnos' son Itys and served him up as a meal to his father.
Aëdon then fled with Chelidonis to her father, who, when Polytechnos came in pursuit of his wife, had him bound, smeared with honey, and exposed to the insects. Aëdon now took pity upon the sufferings of her husband, and when her relations were on the point of killing her for this weakness, Zeus changed Polytechnos into a pelican, the brother of Aëdon into a whoop, her father into a sea-eagle, Chelidonis into a swallow, and Aëdon herself into a nightingale. This myth seems to have originated in mere etymologies, and is of the same class as that about Philomela and Procne.