The plot of CATS is actually based on the poems in T. S. Eliots' book "Old Possums Book of Practical Cats". The first ideas of turning the book into a musical first occurred to Andrew Lloyd Webber in 1972 when he picked up the book at a bookstore in an airport. Immediately he remembered how his mother used to read the poems to him and the thought occurred that he might be able to turn them into an album or something. Eventually Webber wrote a song cycle putting Eliots poems to music and showcased it in his home during an annual festival for his friends and neighbors. After meeting with Valerie, Eliots widow, Webber was both excited and determined to make the poems into a musical. Nearly a decade went by, however, before the composer contacted his director friend, Trevor Nunn, about the possible project. There was no need to create characters and personalities because Eliot had already taken care of that in his works. Each cat described in the poems came with a sort of satiric story about him or herself. This description left each character different and individualized. Somehow, despite the distinction, the odd cat names were tied together with the poem, "The Naming of Cats". It goes into a vast definition, explaining "But I tell you, a cat needs a name thats particular, A name thats peculiar, and more dignified..Names that never belonged to more than one cat". All that was left was to put the poems to music and then to tie them all into a plot line.

Andrew Lloyd Webber and Trevor Nunn had most of the vital musical factors handed to them on a silver platter, courtesy of T. S. Eliot. They were given several characters and their personalities, as well as the poetry to act as lyrics for the songs. Despite all of the high points, there were still some problems. The main complication was that the poems had no relationship or storyline to create a full musical. They needed some element that could tie both the story and the characters together. The answer came when Eliots widow revealed to them some forgotten poems and fragments. With eight lines of poetry, Webber and Nunn found the missing piece they had been looking for. The poem introduced a character named Grizabella, the Glamour Cat, and was truly the missing link to the musical. It described a cat who had left the Jellicle Cats to experience the outside world, recalls the hard times she encountered, her glorious past lost forever. With this character came the song that, though created literally overnight, has been presently recorded by over 170 artists worldwide. This song is the haunting "Memory". The ballad was sung by Grizabella as an emotional outlet, explaining how times goes by so quickly and that memories are the only access to the past. With Eliots secrets uncovered, a thorough success with the musical was closer to reality.

In May of 1997 CATS turned 16 years old, or an amazing112 in feline years. This production has now become the longest running musical on Broadway and the third longest-running musical in the world. It was through hard work and dedication on the part of Andrew Lloyd Webber and Trevor Nunn, along with the use of captivating music, extraordinary choreography, and visual awe to create a show that has gained millions of fans around the world. Perhaps it was just simply the storyline itself that has haunted audiences everywhere. It may also be believed, however, that it was a combination of all the elements. Whatever the case may be, it can most likely be assumed that CATS would not even exist today if it were not for the work of Andrew Lloyd Webber and Trevor Nunn and the poems of T. S. Eliot, along with the secret poem of Grizabella: the Glamour Cat.