divergence

"You can use rules or set theory to dictate timings and note intervals," expands Sandison about their composition strategies. "For instance, you can imagine your melody to run vertically instead of horizontally, so that you're thinking of it as a vertical spiral, running on the spot. There's a thing you can calculate for plants called divergence, which is a ratio of complete turns of spiral leaf positions relative to the number of leaves in that spiral. In plants, this usually gives a Fibonacci number, which is pretty uncanny, but it's basically a natural law that's trying to create optimum distribution of leaf positions, to stop leaves from obscuring each other in sunlight. You can apply a similar idea to a vertical spiral of music, to calculate optimal temporal event positions in a pattern or texture. It doesn't always make for easy listening though," he adds, laughing.