What are macros? Many modern day software synths contain multiple assignable macro controls. These let you map one or more parameters to a single rotary knob or fader. Macros are extremely handy for keeping your project automation lanes tidier. For example, reverb and delay amounts could both be controlled using one macro automation lane. This is also useful in a live performance scenario. We only have two hands to work with, limiting how many controls we can manipulate at once.