A rhythmically simple melody was generated by the program AlComp (algorithmic composer), using a weighted probability between two complementary pitch sets. This melody is played simultaneously by 12 instruments in a ‘staggered unison’, where the attack of each note has been randomised within a possible range of four beats (preserving durations). The rhythmic flow is further developed by constant, sudden changes in tempo. Each instrument takes turns to drop out of the texture for a fixed unit of time. Although each instrument plays in standard 12-tone equal temperament, each is tuned to a different frequency within the range of a half-tone.