Modulation effects alter certain aspects of a sound over time, such as pitch, phase, or delay, to create movement, depth, and texture. Common modulation effects include chorus, flanger, phaser, vibrato, and tremolo, each producing a distinct type of motion.

These effects are used to add richness and character to guitars, keyboards, and other instruments, ranging from subtle enhancement to dramatic, swirling sounds. Modulation is widely used across many styles of music, from classic rock and funk to ambient and modern experimental sounds.