Lejaren Hiller — Illiac Suite for String Quartet

1957

Artists: Lejaren Hiller, Leonard Isaacson · Year: 1957 · Medium: Musical composition for string quartet — score generated by computer · Substrate: ILLIAC I mainframe; Markov-chain and rule-based filtering algorithms; score printed for human performers · Place: Urbana, Illinois, USA · Institution: University of Illinois at Urbana-Champaign Lejaren Hiller and Leonard Isaacson composed the Illiac Suite for String Quartet in 1957 on the University of Illinois's ILLIAC I computer, and it is the earliest completed composition in Western music whose pitches, rhythms, and internal structure were determined by a computer program executing composition rules. The suite has four movements, each written to demonstrate a different procedure: first-species counterpoint, chromatic modification of triadic harmony, rhythmic and metrical transformation, and Markov-chain-based generation using probabilities derived from traditional harmonic progressions. The output — pitches on punched cards — was transcribed by Hiller into standard musical notation and premiered by a string quartet at the University of Illinois in August 1956, with the full four-movement suite completed by early 1957. Hiller was a professional chemist before he was a composer. He had earned a PhD in chemistry from Princeton in 1947, worked at DuPont, and taken a position in the University of Illinois chemistry department in 1952 before shifting, at age 34, toward composition, eventually founding the university's Experimental Music Studio in 1958. Isaacson, his collaborator, was a mathematics graduate student. The ILLIAC I — one of the first-generation American academic supercomputers, 2,800 vacuum tubes, roughly 1,024 words of memory — was shared by the entire university research community; Hiller and Isaacson had to work at night to get enough machine time to run the compositional experiments. What makes the Illiac Suite matter in this archive is that it is the first publicly-realized case of what would become, a decade later, the European Stuttgart-school argument in computer graphics: that a machine can be programmed to execute a set of constraints, produce an output that satisfies those constraints, and that the output can be assessed aesthetically as a work of art. The suite's musical language is not radical — it is largely tonal, recognizably in a post-Bartók idiom — but its procedural logic is. Hiller and Isaacson published their methods in Experimental Music: Composition with an Electronic Computer (1959), the first methodological treatise on algorithmic composition. The suite has been performed continuously since 1957 and is in the repertoire of serious contemporary-music ensembles. It is also a staple reference for any serious genealogy of computer music. Lore Hiller and Isaacson worked on the ILLIAC at night because the machine was oversubscribed by physics and engineering users during the day. They would book three-hour blocks starting at 2 AM, carry their punched-card decks across campus in paper boxes, and spend the first hour finding and correcting the single-character bugs that had caused a previous run to crash. Hiller later said the suite's first movement was more-or-less generated in a single night of successful runs; the fourth movement, which used Markov-chain probabilities, took nearly six months of nightly sessions as Hiller and Isaacson iterated on the probability tables. The ILLIAC I itself was decommissioned in 1962 and scrapped; a single rack of its tubes survives in the University of Illinois history collection. Hiller died in 1994; Isaacson remained at UIUC. Sources • Hiller, Lejaren; Isaacson, Leonard — Experimental Music: Composition with an Electronic Computer (McGraw-Hill, 1959). • University of Illinois Archives — Lejaren Hiller Papers. • Ames, Charles — "Automated Composition in Retrospect: 1956–1986" (Leonardo, 1987).