(from Latin, alea: “dice game”) Any 20th-century music, particularly that of the 1950s and '60s, the composition or performance of which incorporates elements of chance. In aleatory music aspects such as the ordering of a piece's sections, its rhythms, and even its pitches are decided at the moment of performance. When not purely improvising, players follow lists of arbitrary rules or interpreted “graphic” notation that merely suggest the sounds. Charles Ives and Henry Cowell had used such techniques, but John Cage became the principal figure in aleatory; other aleatory composers include Earle Brown (1926–2002), Morton Feldman (1926–87), and Pierre Boulez.
Learn more about aleatory music with a free trial on Britannica.com.
Musicologist Carl Dahlhaus restricted his definition of musical modernism to progressive music in the period 1890-1910:
The year 1890...lends itself as an obvious point of historical discontinuity....The "breakthrough" of Mahler, Strauss, and Debussy implies a profound historical transformation....If we were to search for a name to convey the breakaway mood of the 1890s (a mood symbolized musically by the opening bars of Strauss's Don Juan) but without imposing a fictitious unity of style on the age, we could do worse than revert to [the] term "modernism" extending (with some latitude) from the 1890 to the beginnings of our own twentieth-century modern music in 1910....The label "late romanticism"...is a terminological blunder of the first order and ought to be abandoned forthwith. It is absurd to yoke Strauss, Mahler, and the young Schoenberg, composers who represent modernism in the minds of their turn-of-the-century contemporaries, with the self-proclaimed anti-modernist Pfitzner, calling them all "late romantics" in order to supply a veneer of internal unity to an age fraught with stylistic contradictions and conflicts. (Dahlhaus 1989, 334)
Daniel Albright (2004) dates musical modernism from 1894-5 (Debussy's Prélude à 'L'après-midi d'un faune and Strauss's Till Eulenspiegels lustige Streiche), and considers musical modernism's main features to be comprehensiveness and depth, semantic specificity and density, and Extensions and destructions of tonality.
However, as an alternative to this definition Albright proposes: "Modernism is a testing of the limits of aesthetic construction." Besides eliminating the progress meta-narrative of the above definition, this definition is also capable of application to more the music, artists, and movements considered modernist: Expressionism & New Objectivity, Hyperrealism & Abstractionism, Neoclassicism & Neobarbarism, Futurism & the mythic Method.
Leon Botstein, on the other hand, asserts that musical modernism is characterized by "a conception of modernity dominated by the progress of science, technology and industry, and by positivism, mechanization, urbanization, mass culture and nationalism", an aesthetic reaction to which "reflected not only enthusiasm but ambivalence and anxiety" (Botstein 2007).
Other writers regard the period of musical modernism as extending only to about 1930, and apply the term "postmodernism" to the period after that year (Karolyi 1994, 135; Meyer 1994, 331–32). In contrast, Albright (ibid) cites John Cage's 1951 composition of Music of Changes as the beginning of post-modern music.
In the 1910s, futurists such as Luigi Russolo looked to a future of music liberated to the point of being able to use any sound, even "noises" such as factory and mechanical sounds (Russolo, "The Art of Noises"), while Edgard Varèse created his Poème électronique specifically for the Philips Pavilion at the 1958 Brussels World's Fair with 400 speakers, designed by Le Corbusier with the assistance of Iannis Xenakis (EMF Institute article "Poème électronique").
John Cage and Lou Harrison wrote works in the late 1940s for percussion orchestra. Harrison later wrote for and built gamelans, while Cage popularized extended techniques on the piano in his prepared piano pieces, starting in 1938 (Stephen Drury, "In a Landscape") Starting in the early 1920s, Harry Partch built his own ensemble of instruments, mostly percussion and string instruments, to allow the performance of his theatrical ("corporeal") justly tuned microtonal music (Partch biography page at harrypartch.com).
Albright also points out that there are few traits of postmodernism not present in modernism. Erik Satie and the neoclassicism of Stravinsky is sometimes near indistinguishable with bricolage and polystylism. Surrealist Marcel Duchamp wrote chance music while Cage was still into percussion.
Brian Ferneyhough coined the neologism "too-muchness" to describe the excess of information contained in music exhibiting the New Complexity, and many would argue this applies to its modernist inspirations as well.