The Chorus Effect (kɔ́rəs əfɛ́kt) is a sound effect applied in music to add richness, fullness and an ethereal quality to a sound. This effect is accomplished by layering sounds like guitars, pianos or voices of almost the same pitch and timbre over one another to create a single sound. The Chorus Effect got its name because its sound is comparable to a traditional chorus of voices, performing together in similar tone to achieve this “shimmering” sound.

The Chorus Effect can be generated physically with a choir performing together or with guitarists playing the same piece, or it can be created programmatically with digital signal processing hardware, electronic sound effects units or with specialized effects software and a digital audio workstation. Regardless of the source or method used to achieve it, the Chorus Effect can add an otherworldly quality to any piece of music or live performance.