Cats is a sung-through musical composed by Andrew Lloyd Webber, based on the 1939 poetry collection "Old Possum's Book of Practical Cats" by T. S. Eliot. It tells the story of a tribe of cats called the Jellicles and the night they make the "Jellicle choice," deciding which cat will ascend to the Heaviside Layer and come back to a new life. The musical includes the well-known song "Memory" as sung by Grizabella. As of 2019, "Cats" remains the fourth-longest-running Broadway show and the sixth-longest-running West End show.