Sirens were originally beautiful bird women who lured nearby sailors with their enchanting music and voices to shipwreck on the rocky coast of their island. Although in Greek mythology Sirens are represented as mermaids, they actually dwell on an island in a flowery meadow.
The Sirens are probably best known for their part in the Odyssey where their song lured sailors to their death. Odysseus ordered his crew to plug their ears with wax (on the advice of Circe) so as not to be lured by the Sirens' song. In the story of the Argonauts, Orpheus sang sweetly enough to keep the men from succumbing to the Sirens.