Lloyd Webber began composing the songs in late 1977 as a songwriting exercise, partly because Eliot's book had been a childhood favourite and partly to see if he could write music to predetermined lyrics. The compositions were performed privately for friends but Lloyd Webber had no further intentions for them at the time. After his song cycle Tell Me on a Sunday was televised by the BBC in early 1980, Lloyd Webber began to consider using his musicalizations of Eliot's poems in the same vein for a televised concert anthology.[8] He approached producer Cameron Mackintosh to discuss possible avenues for the songs.[9]
Cats introduced a marketing strategy that set the template for subsequent megamusicals. Early advertisements for the musical did not feature traditional pull quotes (despite many positive reviews) or any of the cast, focusing instead on branding the show itself as the star. It did this by adopting — and then aggressively promoting — a single recognisable image (the cat's-eyes logo) as the face of the show.[321] The cat's-eyes logo was the first globally marketed logo in musical theatre history,[88] and was paired with a tagline ("now and forever") to create what The Daily Telegraph called "one of musical theatre's greatest posters".[322] Such branding emblems proved equally effective for later megamusicals, as seen with the waif Cosette for Les Misérables and the Phantom's mask for The Phantom of the Opera. This advertising method had the additional effect of diminishing the importance of critical reviews, popularising the so-called "critic-proof" status of megamusicals.[321]

Cats are obligate carnivores: their physiology has evolved to efficiently process meat, and they have difficulty digesting plant matter.[103] In contrast to omnivores such as rats, which only require about 4% protein in their diet, about 20% of a cat's diet must be protein.[103] A cat's gastrointestinal tract is adapted to meat eating, being much shorter than that of omnivores and having low levels of several of the digestive enzymes needed to digest carbohydrates.[111] These traits severely limit the cat's ability to digest and use plant-derived nutrients, as well as certain fatty acids.[111] Despite the cat's meat-oriented physiology, several vegetarian or vegan cat foods have been marketed that are supplemented with chemically synthesized taurine and other nutrients, in attempts to produce a complete diet. Some of these products still fail to provide all the nutrients cats require,[112] and diets containing no animal products pose the risk of causing severe nutritional deficiencies.[113]
Finally, the Jellicle patriarch, Old Deuteronomy, arrives before the tribe ("Old Deuteronomy"). He is a wise old cat who "has lived many lives" and is tasked with choosing which Jellicle will go to the Heaviside Layer every year. The cats put on a play for Old Deuteronomy ("The Awefull Battle of the Pekes and the Pollicles"), telling a story about two dog tribes clashing in the street and subsequently being scared away by the Great Rumpus Cat. A sombre moral from Old Deuteronomy is interrupted by a second loud crash, presumably from Macavity, which sends the alarmed cats scurrying. After a quick patrol for Macavity, Old Deuteronomy deems it a false alarm and summons the cats back as the main celebration begins ("The Jellicle Ball"), in which the cats sing and display their "Terpsichorean powers".

^ Jump up to: a b Cameron-Beaumont, Charlotte; Lowe, Sarah E.; Bradshaw, John W. S. (2002). "Evidence Suggesting Pre-adaptation to Domestication Throughout the Small Felidae" (PDF). Biological Journal of the Linnean Society. 75 (3): 361–366. doi:10.1046/j.1095-8312.2002.00028.x. Archived from the original (PDF) on 9 June 2011. Retrieved 29 September 2009.
Cats are known for spending considerable amounts of time licking their coats to keep them clean.[147] The cat's tongue has backwards-facing spines about 500 μm long, which are called papillae. These contain keratin which makes them rigid[148] so the papillae act like a hairbrush. Some cats, particularly longhaired cats, occasionally regurgitate hairballs of fur that have collected in their stomachs from grooming. These clumps of fur are usually sausage-shaped and about 2–3 cm (0.8–1.2 in) long. Hairballs can be prevented with remedies that ease elimination of the hair through the gut, as well as regular grooming of the coat with a comb or stiff brush.[147]
Similar to the original London staging, the set of the 1,200-capacity CATS Theatre is built on a revolving stage floor such that during the overture, the stage and sections of the stalls revolve approximately 180 degrees into place.[160][166] In 1998, the Japanese production underwent major revisions to the choreography, staging and costume designs.[167] Following further revisions in 2018,[168] the current incarnation features 25 named cats, including both Jemima and Sillabub (who have evolved into two separate characters), and an original character named Gilbert.[169]
Domestic cats, especially young kittens, are known for their love of play. This behavior mimics hunting and is important in helping kittens learn to stalk, capture, and kill prey.[172] Cats also engage in play fighting, with each other and with humans. This behavior may be a way for cats to practice the skills needed for real combat, and might also reduce any fear they associate with launching attacks on other animals.[173]

Cats have excellent night vision and can see at only one-sixth the light level required for human vision.[66]:43 This is partly the result of cat eyes having a tapetum lucidum, which reflects any light that passes through the retina back into the eye, thereby increasing the eye's sensitivity to dim light.[75] Another adaptation to dim light is the large pupils of cats' eyes. Unlike some big cats, such as tigers, domestic cats have slit pupils.[76] These slit pupils can focus bright light without chromatic aberration, and are needed since the domestic cat's pupils are much larger, relative to their eyes, than the pupils of the big cats.[76] At low light levels, a cat's pupils will expand to cover most of the exposed surface of its eyes.[77] However, domestic cats have rather poor color vision and (like most nonprimate mammals) have only two types of cones, optimized for sensitivity to blue and yellowish green; they have limited ability to distinguish between red and green.[78] A 1993 paper reported a response to middle wavelengths from a system other than the rods which might be due to a third type of cone. However, this appears to be an adaptation to low light levels rather than representing true trichromatic vision.[79]

One of Nunn's stipulations for agreeing to direct Practical Cats was that actress Judi Dench would be cast in the musical. Lloyd Webber was happy to oblige given her credentials and so Dench joined the company in the dual roles of Grizabella and Jennyanydots. Former Royal Ballet principal dancer Wayne Sleep was offered the part of Mr. Mistoffelees after Lloyd Webber and Mackintosh attended a performance by his dance troupe, one of the many dance showcases they saw in preparation for the musical. Casting for the other roles began in November 1980, with auditions held across the UK for dancers who could also sing and act. There was an initial disagreement over the casting of Nicholas as Rum Tum Tugger; Nunn had misgivings about the actor's laid-back attitude but eventually yielded to Lloyd Webber, Mackintosh and Lynne, all of whom were keen on Nicholas for the role. Sarah Brightman, who had already made a name for herself with the chart hit "I Lost My Heart to a Starship Trooper", arranged a private audition and was cast in an as-then undecided role. By December, the full cast had been assembled.[18]
Colleen Riley is a freelance editor, artist, and immigration paralegal. Her credits include The White Box, Beating the Story, Friendly Local Game Store, Meeples Together, Unknown Armies 3, Infinity, Laser Kittens, More Kittens, Black Mass, and Cavaliers of Mars: Witch-Queen of the Shadowed Citadel. She has also down a lot of work on the Technoir line Technoir, Mechnoir, Morenoir) and the Trinity Continuum (Æon Æxpansion, Distant Worlds, and In Media Res). She serves four (mostly) benevolent feline overlords in Minneapolis, Minnesota. Her Twitter (@wordbunny) and Instagram (colleen_elizabeth_riley) are primarily cat pictures. 
Cats has received many international awards and nominations. The original London production was nominated for six Laurence Olivier Awards in 1981, winning two awards including Best New Musical.[306] Two years later, the original Broadway production won seven Tony Awards, including Best Musical, out of eleven nominations.[307] The London and Broadway cast recordings were nominated for the Grammy Award for Best Musical Theater Album, which the latter won.[308][309] In 2015, the London revival was nominated for — but did not win — two Olivier Awards, including Best Musical Revival.[310]
Lloyd Webber also employs various techniques to help connect the pieces. Namely, the score relies heavily on recurring motifs as well as the use of preludes and reprises.[76] For instance, melodic fragments of "Memory" are sung by Grizabella and Jemima at several points in the show before the song is sung in full,[39] serving to characterize Grizabella and foreshadow her final number.[77][78] Similarly, Lloyd Webber introduces a fugue in the overture, and variations of this theme are then repeated throughout the musical until it is finally resolved as Grizabella ascends to the Heaviside Layer.[79]

Cats, like all mammals, need to get linoleic acid, an essential fatty acid, from their diet. Most mammals can convert linoleic acid to arachidonic acid, as well as the omega 3 fatty acids (eicosapentaenoic acid and docosahexaenoic acid) through the activity of enzymes, but this process is very limited in cats.[121] The Δ6-desaturase enzyme eventually converts linoleic acid, which is in its salt form linoleate, to arachidonate (salt form of arachidonic acid) in the liver, but this enzyme has very little activity in cats.[121] This means that arachidonic acid is an essential fatty acid for cats as they lack the ability to create required amounts of linoleic acid. Deficiency of arachidonic acid in cats is related to problems in growth, can cause injury and inflammation to skin (e.g. around the mouth) decreased platelet aggregation, fatty liver, increase in birth defects of kittens whose queens were deficient during pregnancy, and reproductive failure in queens.[121] Arachidonic acid can also be metabolized to eicosanoids that create inflammatory responses which are needed to stimulate proper growth and repair mechanisms in the cat.[125]
Preformed vitamin A is required in the cat for retinal and reproductive health. Vitamin A is considered to be a fat-soluble vitamin and is seen as essential in a cat's diet. Normally, the conversion of beta-carotenes into vitamin A occurs in the intestine (more specifically the mucosal layer) of species, however cats lack the ability to undergo this process.[121] Both the kidney and liver are contributors to the use of vitamin A in the body of the majority of species while the cats liver does not produce the enzyme Beta-carotene 15,15'-monooxygenase which converts the beta-carotene into retinol (vitamin A).[122] To summarize: cats do not have high levels of this enzyme leading to the cleavage and oxidation of carotenoids not taking place.[120]
Since kitten diets are very high in calories, ingredients must be implemented to ensure adequate digestion and utilization of these calories. Choline chloride is an ingredient that maintains fat metabolism.[42] Biotin and niacin are also active in the metabolism of fats, carbs and protein.[42] Riboflavin is also necessary for the digestion of fats and carbohydrates.[42] These are the main metabolism aids incorporated into kitten diets to ensure nutrient usage is maximized.
Vitamin A is required in kitten diets because cats cannot convert carotenes to retinol in the intestinal mucosa because they lack the enzyme so this vitamin must be supplement in the diet.[24][42] Vitamin E is another required vitamin in kitten diets seeing as deficiency leads to steatitis, causing the depot fat to become firm and yellow-orange in colour, which is painful and leads to death.[42] Also, vitamin D is an essential vitamin because cats cannot convert it from precursors in the skin.[24]
The origin of the English word cat (Old English catt) and its counterparts in other Germanic languages (such as German Katze), descended from Proto-Germanic *kattōn-, is controversial. It was thought traditionally to be a borrowing from Late Latin cattus, 'domestic cat', from catta (used around 75 AD by Martial),[22][23] compare also Byzantine Greek κάττα, Portuguese and Spanish gato, French chat, Maltese qattus, Lithuanian katė, and Old Church Slavonic kotъ (kot'), among others.[24]