Uses the length-pattern active components to pick up the corresponding symbols from the symbol-pattern. This simulates the process used in analog drum machines, which send the triggering pulses to a synth, where the melodic line is supplied by the player. This is very handy tool if you use two or more triggering length-patterns and one symbol-pattern, and is analog to having 2 or 3 rhythmic lines coming from a drum machine, where all resulting instruments will follow your keyboard input.
