Designing patches comprised of subsystems that work together as a small tight band can be exhilarating. Achieving variety and contrast with a single patch is a test of a composer's resourcefulness in the use of variation, transformation, overlay, and transition techniques. All the musical variables are immediately available for change because they represent the operations in a wavetrain produced by a specific collection of electrical variables. Electronic instruments are designed to generate, control, and interact internally with their own waves as well as to provide interactive resources for including external generators of wavetrains. Such forms tend to be self-regulating.
Automatic regulators come into being and play during the evolution of a living structure.
The formal unfolding is guided organically from within in response to external forces. A decision is governed by the interaction of predispositions with the available environmental alternatives. Real-time composition is closely related to higher biological systems which, though internally governed, are responsive to external control information. Cybernetics and systems theory are valuable tools for investigating the nature of ephemeral forms. Cybernetics is concerned with probabilistic rather than deterministic systems.