Main Sketch Another aspect of time flow is achieved through a totally different strategy. The first was mainly combinatorial (algorithmic). The one used for the two percussions (two bass drums and two snares) is based on a computational strategy. The Verhulst equation xn = x * lambda * (1-x) is used here. Starting from a same initial value x, we apply n iterations, and obtain a series of values that simulates chaotic perturbation as we can see in the graph below: Two streams starting with the same value :