Spring

A value that chases a target and overshoots a little before settling.

This is the difference between a drawing that answers the music and one that reads as a meter. Setting a size straight from a beat makes it snap, because the number snaps. Pushing a spring with the beat instead gives the growth a beginning, a peak and a recovery, which is what a physical object does and what an eye expects.

Beats should call kick, never write value. A kick adds speed, so two hits close together add up instead of the second one cancelling the first.