Two Pioneering Projects from the Early History of Computer-Aided Algorithmic Composition The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Citation Ariza, Christopher. “Two Pioneering Projects from the Early History of Computer-Aided Algorithmic Composition.” Computer Music Journal 35.3 (2011): 40-56. Web. 20 Jan. 2012. © 2011 Massachusetts Institute of Technology As Published http://dx.doi.org/10.1162/COMJ_a_00068 Publisher MIT Press Version Final published version Citable link http://hdl.handle.net/1721.1/68626 Terms of Use Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. Christopher Ariza Massachusetts Institute of Technology Two Pioneering Projects Music and Theater Arts, 4-246 77 Massachusetts Avenue from the Early History Cambridge, Massachusetts 02139-4307 USA of Computer-Aided [email protected] Algorithmic Composition Lejaren Hiller’s 1970 chapter, “Music Composed new techniques. Further, each was likely a historical with Computers: An Historical Survey” (Hiller first. The work of Caplin and Prinz in 1955 may 1970) contains numerous descriptions of projects be the first use of a computer to generate not just in the computer generation of musical structures. sound (as was done as early as 1950 or 1951; see By then, just over ten years after the publication Doornbusch 2004), but new musical structures. of Hiller’s and Leonard Isaacson’s seminal book The work of Padberg in the early 1960s may be the Experimental Music (Hiller and Isaacson 1959), a first academic dissertation in CAAC, as well as the startling number of experiments in generative music first research and software in CAAC published by a with early computers had been completed. Hiller’s woman. early research, compositions, and publications This article not only details the historical con- established him as a leader in the then-emerging text and implementation of these projects for the field of computer-aided algorithmic composition first time, but offers original recordings and new (CAAC). Some researchers, likely inspired by Hiller realizations of these early computer-aided composi- and Isaacson’s 1956 Illiac Suite string quartet, even tions. These audio materials are available on-line at duplicated their instrumentation: in an amusing www.flexatone.net/docs/cmj35-3.zip, and will also footnote, Hiller writes that “it is curious to note be included on the Computer Music Journal Sound how many computer pieces have been written for and Video Anthology DVD accompanying the next string quartet . particularly since string-quartet issue (35:4, Winter 2011). performers seem to be among the least receptive to This research would not have been possible newer compositional ideas such as computer music” without the continuing contributions of the original (Hiller 1970, p. 70). authors; numerous personal correspondences with Hiller’s prominence in a young and decentralized both Caplin and Padberg have provided critical field led many independent researchers to contact details on their projects. It is a great fortune that, him directly. He became, it seems, a repository of through Hiller’s desire to document the work information (often obtained only through direct completed in the field, and through the willingness correspondence). Although Hiller’s chapter reports of Caplin and Padberg to revisit and discuss work on numerous projects that are now well known and they completed a half-century ago, we can today independently documented, buried in the historical listen to some of the earliest attempts at composing survey are a few remarkable endeavors of significant music with a computer. historical importance that have not hitherto been fully documented, corroborated, or heard. This article brings forth two of these projects, the work of David Caplin and Dietrich Prinz, and the work of The First Ten Years of Computer-Aided Algorithmic Sister (then Mother) Harriet Padberg. In his chapter, Composition Hiller describes both of these projects primarily through letters he received from the authors. The work of Hiller and Isaacson, leading to the Both projects were pioneering: they began with completion of the Illiac Suite string quartet, is often little or no knowledge of other applications of credited as the first extensive use of a computer computers to music generation, and they explored to create music with algorithms (Dodge and Jerse 1997, p. 373). As Hiller frequently notes, however, Computer Music Journal, 35:3, pp. 40–56, Fall 2011 there were earlier experiments. The most well- c 2011 Massachusetts Institute of Technology. documented of these experiments is the song Push 40 Computer Music Journal Button Bertha. This piece was the result of program- himself and Prinz, that created music using two dis- ming by Douglas Bolitho and Martin L. Klein, with tinct methods. The first approach employed the com- lyrics written by Jack Owens (Anonymous 1956a, bination of precomposed melodic fragments based 1956b, 1956c; Darreg 1957; Klein 1957; Pierce 1961; on the dice games attributed to Mozart (Hiller 1970; Hiller 1970; Ames 1987). On 15 July 1956, Push Gardner 1974; Hedges 1978). The second approach Button Bertha aired on the television program built melodic lines with conditional probabilities. “Adventure Tomorrow,” less than one month before Hiller, in Experimental Music (Hiller and Isaacson 9 August 1956, the date Hiller staged a performance 1959), mentions this research, citing as his source an of an incomplete Illiac Suite at the University of Illi- earlier, though undated, letter from R. J. Lunbeck. nois (Hiller and Isaacson 1959). The Illiac Suite was Caplin was well suited to design a computer not completed until November, three months later. music system in 1955: he had experience with The work of Caplin and Prinz in 1955 thus preceded music, had worked with some of the earliest both the Illiac Suite and Push Button Bertha. computers, and had abundant access to a newly From 1955 to 1965 there were numerous exper- installed machine in his workplace. Caplin was born iments in CAAC. In addition to more well-known in 1927 in Leeds, England. Although lacking formal projects, such as Hiller and Robert Baker’s MUsic music training, he studied music independently and SImulator-Interpreter for COMpositional Proce- began composing at the age of nine. He entered dures (MUSICOMP; Baker 1963; Hiller 1967, 1969), the London School of Economics (LSE) in 1944 Gottfried Michael Koenig’s Project 1 (first tested in at age 17. In his last two years at the LSE he 1964; Koenig 1970), and Iannis Xenakis’s Stochastic specialized in mathematical statistics, and notes Music Program (Xenakis 1965), there appear to be at as particularly influential seminars given by Karl least 20 other independent efforts at CAAC within Popper. Upon leaving the LSE he was drafted into this period (Ariza 2005a). the office of the Scientific Advisor to the Air The work of Caplin and Prinz, as well as that of Ministry. There, he began work in what was then Padberg, is found at opposite boundaries of this ten- called operational research, building mathematical year period. Using computers, they implemented models of real-world problems. In 1950 he was and extended well-known approaches to procedural hired by Petrocarbon Ltd. (and its operating arm or algorithmic composition that had formerly been Petrochemicals Ltd.), and began to apply operational carried out without computers. These techniques research in the petrochemical industry. Daunted by and their historical origins will be subsequently the time it took to solve problems, Caplin looked explained in depth. Caplin implemented the famous to the nearby Ferranti Mark I computer, delivered dice games attributed to W. A. Mozart; Padberg to Manchester University in 1951 (Tweedale 1993), employed serial techniques along with a text- for more efficient solutions. He then began studying to-pitch mapping procedure strikingly similar programming. According to Caplin, it was Prinz, to Guido of Arezzo’s (ca. 991–1033) vowel-to- a member of Ferranti’s instrument department pitch mapping routines defined in Micrologus since 1947 (UK National Archive for the History (Guido of Arezzo 1978 [ca. 1026]). Both, however, of Computing 2005), who originally taught him quickly extended these historical approaches toward how to program (Caplin 2008). Petrochemicals Ltd. more idiomatic designs, recognizing the new and was later acquired in 1955 by Shell Chemical, the powerful opportunities available with computer company at which Caplin continued his work both implementation. in London and Amsterdam (Caplin 2008). Starting around September 1955 Caplin, then based in London, would commute from London The Work of David Caplin and Dietrich Prinz to the Koninklijke/Shell-Laboratorium in Ams- terdam (KSLA, now called the Shell Technology On 21 September 1960 Hiller received a letter from Centre Amsterdam). Caplin, placed in charge of eco- Caplin describing computer programs, written by nomics and planning, developed linear programming Ariza 41 routines on the KSLA’s new computer, a Ferranti a computer group and began development of the Mark I∗ (the star is an indication of a model with Ferranti Mark I (Tweedale 1993). The Mark I, gen- revised hardware). Yet, when time permitted, he erally considered the first digital, stored-program explored applications of the computer to music. computer made commercially available (Moreau This work involved not only the generation of mu- 1984; Cambell-Kelly and Aspray 1996), was based on sical structures, but direct synthesis of elementary a computer developed at Manchester University in sounds (Lunbeck 2005a; Caplin 2008). While Hiller the late 1940s called the Manchester Mark 1 or the and Isaacson, describing these experiments, state Small-Scale Experimental Machine (SSEM; Napper that “the coding of this problem was carried out by 2005). Ferranti sold a total of nine Mark I computers. D. A. Caplin” (Hiller and Isaacson 1959, p.