The legend of the dying swan's melancholy song is given its first expression in extant Greek literature by Aeschylus in 458 B.c., and it has obsessed poets, commentators, and natural historians ever since. Poets like Tennyson may sing of the dying swan's ‘music strange and manifold’, unaffected by the scoffing doubts expressed by ancient scientists and modern editors of classical texts. But do dying swans really ‘sing’? The answer has been known now for over a century and a half, and is mentioned briefly in one or two works on ancient zoology such as C. J. Sundevall's Die Thierarten des Aristoteles (Stockholm, 1863), p. 152, and O. Keller's Die antike Tierwelt (Leipzig, 1913; reprinted 1963), ii.215. English commentators on ancient texts and D'Arcy Thompson's standard Glossary of Greek Birds (second edition, London and Oxford, 1936; reprinted 1966), however, tend either to neglect or unscientifically to dismiss the correct explanation. For this reason a restatement of the facts both ancient and modern seems advisable.