Phaser, flanger, and chorus effects are staples in just about every form of music. They infuse musical compositions with motion and texture, and pedals that create these effects offer musicians an easy way to add new dimension or completely transform the vibe of a song. Think Anthony Jackson’s soupy bass groove on “For the Love of Money,” Eddie Van Halen’s jet-like riff on “Unchained,” or Kurt Cobain’s dreamlike rhythm on “Come As You Are.”
All three effects fall under the modulation category. What that means is that they all modulate—or cyclically change—some aspect of your instrument signal. What distinguishes one from another is which part of your signal they change and how they change it.