Chorus effects attempt to do as their name suggests – transform one sound into many. This is achieved by playing copies of the original signal back with slight variations in pitch and delay time. The Hammond organ had a primitive version of chorusing, and you may already have noticed the similarity to Ken Townsend’s ADT effect employed by the Beatles at Abbey Road.
The technique got another airing in the 70s, when it was used to thicken the sound of string machines such as the Solina String Ensemble.
However, most modern choruses can be traced back to Roland. Yep, them again! In 1975, Roland released their much-lauded JC-120 Jazz Chorus guitar amplifier which, as you’d probably guess, featured the first appearance of the company’s ‘Dimensional Space Chorus’ effect. This fabulous fattener was effectively too good to be contained, and by 1976, it had been distilled into a stompbox: the Boss Chorus Ensemble CE-1. In 1979, Roland trundled out a dedicated rack-mountable unit: the Dimension-D.
The chorus effect became all but compulsory in the 1980s. It was the sound of the New Wave, and MTV-ready rockers slathered it all over their basses and guitars. Chorus circuits found their way into synths, too. Roland’s valiant effort to bring low-cost polyphonic synths to the masses resulted in a number of single-oscillator instruments with a chorus tacked onto the end of the signal path to add the necessary width. Instruments that didn’t have a chorus feature were more often than not plugged into a chorus pedal. It was the 80s, after all!
Needless to say, the originators would soon be joined by a host of imitators. By the end of the 70s, Electro-Harmonix had brought out their Small Clone pedal. It was pretty popular at the time, but these days it’s positively deified, thanks to being championed by Nirvana’s Kurt Cobain.
“Chorus was all but compulsory in the 1980s”
Moderately successful upon release, the Small Clone became an instant classic the moment Kurt Cobain patched one in