Live coding intervenes in an ongoing process by modifying its laws (the program text), not its immediate state

A key philosophical distinction in Rohrhuber’s analysis: in most performance, the performer changes the state of an ongoing process (playing a note, turning a knob). Live coding instead modifies the laws governing the process — the program itself. This is analogous to the physics distinction between the Heisenberg picture (state) and the Schrödinger picture (laws/wavefunction). Changing the program means the corrected text loses the causal picture of the current execution state; the live coder must simultaneously hold the intended musical outcome, the existing running state, and the new code text. This tripartite tension is distinctive to the live coding mode of performance.

Examples

Turning a filter cutoff knob changes state. Rewriting the function that generates cutoff values changes the law. Both may produce the same audible transition, but one modifies state and the other modifies the generative rule.

Assessment

In one paragraph, explain the difference between state-based and law-based musical intervention. Give a concrete example of each using a live coding tool of your choice.