Hiller, Lejaren; Isaacson, Leonard
«Illiac Suite: Quartet No. 4 for strings»

With every movement of their «Iliac Suite» Hiller and Isaacson experiment with a different principle. The first movement is founded on series of tones generated by chance and subjected, in twos, to the rules of sixteenth century counterpoint. The second movement relies on rigidly applied counterpoint. The third movement is a study of rhythmic and dynamic variations, and the fourth draws from twelve-tone music.
The «ILLIAC Suite» (also «String Quartet No. 4«) is the first piece of music composed by a digital computer. It emerged from experiments by the American musicians and scientists L. A. Hiller and L. M. Isaacson, who wanted to enlist the mainframe computer «ILLIAC I» to see how much composition, as a system with rules specific to genre and style, can be implemented as computer algorithms. The first three movements of the string quartet are based on traditional rules of composition (simple polyphony, counterpoint, tone-row techniques), but the fourth movement works with so-called «Markow chains,» thus making a technical and mathematical principle the sole basis of the music. After it had been computed, the synthetically created score was transcribed into traditional notation and played on normal instruments. The «ILLIAC Suite» is not the first algorithmic composition, but has predecessors, e.g. the 1821 mechanical «Componium» by Dietrich Nicholas Winkel and Wolfgang Amadeus Mozart's «musikalisches Würfelspiel» (Mozart's Dice Game).