A death song
(Noun)
Synonyms:
  1. dirge
  2. elegy
  3. chant du cygne (French)
*A final act or performance
(Noun)
Synonyms:
  1. farewell
  2. farewell performance
  3. last-hurrah
  4. peroration
  5. coda
  6. crowning achievement
  7. dying words
  8. envoi
  9. epilogue
  10. parting-shot
  11. famous-last-words
  12. final appearance
  13. final gesture
  14. final performance
  15. goodbye
  16. last shot
  17. last-words
  18. parting song