Swan song

>The last or final work, effort or performance.
>Final composition or performance, given before dying or retirement.

The term swan song originates from the legend that, while they are mute during the rest of their lives, swans sing beautifully and mournfully just before they die.
This isn’t actually the case – swans, even the inaccurately named Mute Swans, have a variety of vocal sounds and they don’t sing before they die.
Nevertheless, poetic imagery proved to be more attractive than scientific method and many poets and playwrights made use of the fable.

Example

>This game is our swan song so let’s win it!
>If I had known this play would be my swan song. I would have tried to enjoy it more.