Modulation

Modulation is the process that brings synthesis to life. Rather than leaving parameters fixed, you route a modulation source — an envelope, an LFO, a step sequencer, velocity, or the mod wheel — to a destination such as filter cutoff, pitch, volume, or an effect setting, so the value changes on its own over time. This is what separates a lifeless, static patch from an evolving, expressive one. Modern synths make routing visual and easy, often with a modulation matrix or drag-and-drop assignment, and let you scale how much each source affects its destination. Learning to think in terms of sources and destinations is the single biggest step toward designing sounds that move, breathe, and respond to how they are played.