Chorus can be heard on acoustic sources such as choires, 12-string guitars and string ensembles. It was made avaliable as an effect pedal in the early 1970’s when technology allowed for this effect by taking an audio signal and mixing it with one or more delayed, pitch-modulated copies of itself. The pitch of the added voices is typically modulated by an LFO, which makes the overall effect similar to that of a flanger, except with longer delays and without feedback.
The Black Sheep Analog