echo

How the last frame comes back this frame. The default reads the zoom, spin and drift for the mood, and settles all three towards neutral as the music goes quiet.

The mood alone does not settle them. It reads 0 in a silence, which gives a drawing its calm zoom rather than none, and a trail that swims at the same rate with nothing playing is the clearest way for a drawing to look like a screen saver. A paused player or a silence holds the trail still.