Cats is a sung-through musical with music by Andrew Lloyd Webber. It is based on the 1939 poetry collection Old Possum's Book of Practical Cats by T. S. Eliot. The musical tells the story of a tribe of cats called the Jellicles and the night they make the "Jellicle choice" by deciding which cat will ascend to the Heaviside Layer and come back to a new life. As of 2024, Cats remains the fifth-longest-running Broadway show and the eighth-longest-running West End show.