Order of colours in the rainbow, or visual spectrum: (Red, Orange, Yellow, Green, Blue, Indigo, Violet)
Richard Of York Gave Battle In Vain.
Order of taxonomy in biology: (Kingdom, Phylum, Class, Order, Family, Genus, Species)
Kids Prefer Cheese Over Fried Green Spinach.
Order of geological time periods: (Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Permian, Triassic, Jurassic, Cretaceous, Paleocene, Eocene, Oligocene, Miocene, Pliocene, Pleistocene, Recent)
Cows Often Sit Down Carefully. Perhaps Their Joints Creak? Persistent Early Oiling Might Prevent Painful Rheumatism.
Order of Mohs hardness scale, from 1 to 10: (Talc, Gypsum, Calcite, Fluorite, Apatite, Orthoclase feldspar, Quartz, Topaz, Corundum, Diamond)
Toronto Girls Can Flirt, And Other Queer Things Can Do.
The order of sharps in music, called the “circle of fifths”: (F, C, G, D, A, E, B)
Father Charles Goes Down And Ends Battle.
And in reverse for flat keys the mnemonic can be neatly reversed:
Battle Ends And Down Goes Charles’ Father.
In general terms, mnemonics are mental techniques aimed at helping us to learn and remember specific items of information. They provide organization in terms of which we can more easily comprehend and remember information that has, as we say, little rhyme or reason for us. Mnemonics contrive meaning, sometimes of a quixotic sort, for information we find relatively meaningless and, because of this, they are sometimes called ‘artificial memory’.
To illustrate further, consider the problem of remembering the number of days in each month of the year. A commonly used mnemonic runs, ‘Thirty days hath September; April, June, and November; all the rest have thirty-one; excepting February alone; which has twenty-eight days clear; and twenty-nine in each leap year.’ This jingle helps by rearranging the information, categorizing it, compressing it, and introducing rhythm and rhyme. A less widely used mnemonic consists of counting each successive month on our knuckles. Long months fall on the knuckles, short months on the hollows between. Once more, organization makes the information easier to grasp and remember.
The mnemonics just mentioned achieve organizations which are relatively conventional and publicly comprehensible. But many mnemonics devised by individuals for private use achieve an idiosyncratic organization involving the person’s unique background of experiences, visual imagery, and other features that are not readily communicable. Sir Donald Tovey, for example, was a highly accomplished musician who happened to assign a number to each location on the musical stave. When he wanted to memorize any telephone number, he translated each successive digit into the correspondingly numbered location on the stave, and remembered the resulting tune. Idiosyncratic mnemonics may work well for the individual concerned, but if he tries to explain them publicly they seem tortuous, arbitrary, and even laughable. They also imply that he cannot easily comprehend the information. Because of this, mnemonics are discussed less than they are used, and there is a lack of systematic data on their uses and abuses in everyday life.
The best way to learn and remember information is to ‘understand’ it. Most people appreciate this fact. But they may sometimes want to have in their head information which is not readily ‘understandable’. When this happens, the trick is to recognize that a mnemonic is indeed a substitute form of comprehension, and to deploy and devise our mnemonics intelligently, with due regard for what they enable us, and do not enable us, to achieve. Unfortunately, but not surprisingly, it is generally the case that the people with most need of mnemonics tend also to be the least able to devise them intelligently and evaluate their advantages and disadvantages.
— Ian M. L. Hunter (Published 1987)
World of the Mind. The Oxford Companion to the Mind. Second Edition. Copyright © Oxford University Press, 2004. All rights reserved.