This Ableton tutorial covers how Vector Grain switches from MIDI-triggered playback into a self-running granular looper, useful for building evolving pads, atmospheres, and textures. Setting the Grains control to a fixed number removes MIDI dependency and puts the device into continuous grain generation. The Lock parameter ties that generation to Live's transport, so grains only run when playback is active.
The Emitter, found in the Particle Systems tab, introduces a creation-and-destruction cycle to the grain stream. Rate sets how quickly new grains are spawned, and Life sets how long each grain persists before it disappears. The total number of grains that can coexist at any moment is always capped by the Grains control, so these three parameters work as a system rather than independently.