Control stream
A control stream is a collection of numbers (each number is called an event), sometimes empty, that are the result of control computations. Roughly analogous to a MIDI controller.
A signal can be converted into a control stream by zipping a series of logical times with an audio signal so each control value is derived from a sample.
A control stream can also be operated on by delaying, merging, pruning or resynchronizing them, much like event streams in reactive programming.