Aleatoricism, the noun associated with the adjectival aleatory, is a term popularised by the musical composer Pierre Boulez, but also Witold Lutoslawski and Franco Evangelisti, for compositions resulting from “actions made by chance”, with its etymology deriving from alea, Latin word for “dice”. It now applies more broadly to art created as a result of such a chance-determined process.

The term was first used “in the context of electro-acoustics and information theory” to describe “a course of sound events that is determined in its framework and flexible in detail”, by Belgian-German physicist, acoustician, and information theorist Werner Meyer-Eppler. In practical application, in compositions by Mozart and Kirnberger, for instance, the order of the measures of a musical piece were left to be determined by throwing dice, and in performances of music by Pousseur (e.g., Répons pour sept musiciens, 1960), musicians threw dice “for sheets of music and cues”. However, more generally in musical contexts, the term has had varying meanings as it was applied by various composers, and so a single, clear definition for aleatory music is defied. Aleatory should not be confused with either indeterminacy, or improvisation.

The aleatoric technique can take two forms:

random elements are revealed during work – determining the composition from the result of the dice or coin roll, drawing from the deck of cards, using the sound generator;
random elements are introduced by the performer according to notation.
Various elements of composition may be subject to indeterminism

Charles Hartman discusses several methods of automatic generation of poetry in his book The Virtual Muse.

Automatic writing or psychography is a claimed psychic ability allowing a person to produce written words without consciously writing. The words purportedly arise from a subconscious, spiritual or supernatural source. Scientists and skeptics consider automatic writing to be the result of the ideomotor effect and even proponents of automatic writing admit it has been the source of innumerable cases of self-delusion. Automatic writing is not the same thing as free writing.

Automatic drawing was pioneered by the English artist Austin Osman Spare who wrote a chapter, Automatic Drawing as a Means to Art, in his book, The Book of Pleasure (1913). Other artists who also practised automatic drawing were Hilma af Klint, André Masson, Joan Miró, Salvador Dalí, Jean Arp, André Breton and Freddy Flores Knistoff.

The technique of automatic drawing was transferred to painting (as seen in Miró’s paintings which often started out as automatic drawings), and has been adapted to other media; there have even been automatic “drawings” in computer graphics. Pablo Picasso was also thought to have expressed a type of automatic drawing in his later work, and particularly in his etchings and lithographic suites of the 1960s.

Automatic drawing (distinguished from drawn expression of mediums) was developed by the surrealists, as a means of expressing the subconscious. In automatic drawing, the hand is allowed to move “randomly” across the paper. In applying chance and accident to mark-making, drawing is to a large extent freed of rational control. Hence the drawing produced may be attributed in part to the subconscious and may reveal something of the psyche, which would otherwise be repressed. Examples of automatic drawing were produced by mediums and practitioners of the psychic arts. It was thought by some Spiritualists to be a spirit control that was producing the drawing while physically taking control of the medium’s body.

Most of the surrealists’ automatic drawings were illusionistic, or more precisely, they developed into such drawings when representational forms seemed to suggest themselves. In the 1940s and 1950s the French-Canadian group called Les Automatistes pursued creative work (chiefly painting) based on surrealist principles. They abandoned any trace of representation in their use of automatic drawing. This is perhaps a more pure form of automatic drawing since it can be almost entirely involuntary – to develop a representational form requires the conscious mind to take over the process of drawing, unless it is entirely accidental and thus incidental. These artists, led by Paul-Émile Borduas, sought to proclaim an entity of universal values and ethics proclaimed in their manifesto Refus Global.

As alluded to above, surrealist artists often found that their use of “automatic drawing” was not entirely automatic, rather it involved some form of conscious intervention to make the image or painting visually acceptable or comprehensible, “…Masson admitted that his ‘automatic’ imagery involved a two-fold process of unconscious and conscious activity….”

Aleatorism (also indeterminism) – a composing technique in contemporary music consisting in allowing the composer for randomness when performing a composition in the scope of some of its elements, thus assuming the uniqueness of the performance itself. The creator of the term is Pierre Boulez. John Cage is considered a pioneer of aleatorism. Aleatorism is one of the features of instrumental theater. Musicians likeSylvano Bussotti determined their music using graphic notation.

Aleatoricism is associated with surrealism. According to Józef Michał Chomiński, “sources of surrealism are subconscious, uncontrolled, spontaneous mental processes. Therefore, pure accidentalness becomes the driving force of artistic activities, “and surrealism” breaks the form so much into separate elements that they lose their relationship with each other and allow the emergence of new, unexpected relationships and associations (aleatorism), or creates a form of heterogeneous independent elements (collage). ”

The author may use a random factor at the stage of composing (as in dadaism ), or leave some freedom to the performer. In musical notation, it consists of a deliberately vague notation, e.g. an irregular wavy line on a staff instead of specific sounds. Another method is to build compositions from short components, the order of which is chosen randomly during the performance of the work (e.g. Klavierstück XI Stockhausen ).

Sometimes, in addition to the composed work, other non-recordable sounds are allowed, such as in one of John Cage’s compositions, in which 12 radio receivers were used that were accidentally tuned during the performance of the song. Other methods used in aleatoric music include composing for an instrumental ensemble of any composition, organized ad hoc, in a purely random manner (see: theory of open form ).

Aleatorism should not be confused with improvisation found in, for example, jazz music, as freedom is manifested here in a different way. At the same time, the form of controlled aleatorism can be represented by improvisation within Wolfgang Fortner within limits of pitch.

From an acoustic point of view, each performance of a piece is an aleatoric phenomenon, because precise musical notation does not equal absolute precision of performance.

The term aleatory was first coined by Werner Meyer-Eppler in 1955 to describe a course of sound events that is “determined in general but depends on chance in detail”. When his article was published in English, the translator mistakenly rendered his German noun Aleatorik as an adjective, and so inadvertently created a new English word, “aleatoric”. Pierre Boulez applied the term in this sense to his own pieces to distinguish them from the indeterminate music of John Cage. While Boulez purposefully composed his pieces to allow the performer certain liberties with regard to the sequencing and repetition of parts, Cage often composed through the application of chance operations without allowing the performer liberties.

Another composer of aleatory music was the German composer Karlheinz Stockhausen, who had attended Meyer-Eppler’s seminars in phonetics, acoustics, and information theory at the University of Bonn from 1954 to 1956, and put these ideas into practice for the first time in his electronic composition Gesang der Jünglinge (1955–56), in the form of statistically structured, massed “complexes” of sounds.

Aleatoric techniques are sometimes used in contemporary film music, e.g., in John Williams’s film scores[clarification needed] and Mark Snow’s music for X-Files: Fight the Future.

In film-making, there are several avant-garde examples, including Andy Voda’s Chance Chants, which features Alison Knowles’ computer poem “House of Dust”.

Fred Camper’s SN (1984, first screening 2002) uses coin-flipping for one section to determine which three of 16 possible reels to screen and what order they should go in, a design that allowed for 3360 permutations of the viewable film.

Film scholar Barry Salt directed the 1971 film Six Reels of Film to Be Shown in Any Order, which involves aleatory.