Ex machina
(1994/95) computer-generated sound
The primary focus of my composition Ex machina is a canon (in the musical and literal sense of “rule”)— certainly one of the oldest compositional processes in Western music, and one in which there is a sense of “automation” determined by the rule. The canon in this case was generated by the computer using the programming environment Max (after the computer music pioneer Max Mathews), and although it is heard in the piece as a “piano” (perhaps conjuring images of a frazzled performer), this canon could not be “played” because the time interval between the leader and follower is a variable number of milliseconds rather than a specified and constant number of beats or measures. The rhythmic displacement between leader and follower is never greater than a single sixteenth-note. This canon is part of a palindrome which, with the exception of the opening material and modifications which do not alter the placement of important structural events in time, is the large-scale form of the piece. There are therefore symmetries in counterpoint (between the voices of the canon, which are identical) and in time from a central point in the piece extending in both directions.
—Robert Gibson
duration: ca. 6:15