swan song

The swan song is a metaphorical phrase for a final gesture, effort, or performance given just before death or retirement. The phrase refers to an ancient belief that swans sing a beautiful song just before their death since they have been silent (or alternatively not so musical) for most of their lifetime. The belief, whose basis has been long debated, had become proverbial in ancient Greece by the 3rd century BC and was reiterated many times in later Western poetry and art. Swans learn a variety of sounds throughout their lifetime. Their sounds are more distinguishable during courting rituals and not correlated with death.