Word of the Day: Aleatory

Aleatory or aleatoric means pertaining to chance; literally, depending on a roll of the dice (from the Latin alea, a dice game). Anything exploiting the principle of randomness can be termed aleatory. An insurance policy, for example, is an aleatoric contract, in that it depends on a chance occurence (accident, death, fire, flood, or what have you).

The principle of randomness has been applied to literature, music, and other forms of art, with interesting results. The random poetry generators noted in previous posts produce aleatory verse. A mathematical process known as a Markov chain (after the Russian mathematician Andrei Markov) is used to generate the literary output. Where X₁, X₂, X₃, ... is a series of random variables,

Pr(X_n+1 = x|X_n = x_n,…,X₁ = x₁,X₀₀) = Pr(X_n+1 = x|X_n = x_n).

In order to produce lines of verse which resemble recognizable language, certain linguistic parameters might be defined in a random text generator, with Markov chains embedded within larger programs. For example, words might be identified by their parts of speech, and a preposition programmed always to be followed by a noun, the specific noun generated by a Markov chain.

Pierre Boulez, the French composer, has experimented extensively with aleatoric music. Barry Salt, the film scholar, in 1971 made a film called Permutations (a.k.a. Six Reels of Film to Be Shown in Any Order). Each reel contains two scenes whose implications vary depending on the order in which the reels are shown. The projectionist is supposed to roll dice in order to determine the reel order. Jeffrey Harrison, a Guggenheim fellow who's been published in The New Yorker, The Paris Review, The Yale Review, and many other distinguished anthologies and journals, has experimented with aleatoric poetry. And now, in the 21st century, any dummy with a computer can attempt what in 1921 took a million monkeys.