Electric guitar is the signifying ingredient of rock and roll, the primal essence demarcating it from the dominating horns and keyboards of its boogie woogie roots. And if we were to seek a point where good old rock and roll became a modern thing we simply call rock music, there's no better benchmark than that electric guitar effect known as the wah wah pedal. When did modern rock begin? Not before the wah wah pedal.

Prior to the wah wah's introduction in 1966, electric guitarists effected their sound with methods that had been around for a long time. The soaking wet reverberation of surf music's spring tank units and the echo of tape delay were based on technology that dated back to the 1930's. Even the psychedelic sustain of the "fuzz box" was built around the simple concept of overdrive and distortion, evident on early recordings whenever an electric guitarist really cranked it up. The wah wah was something completely new.

As shown in the hour-long documentary Cry Baby: The Pedal That Rocks The World, the wah wah pedal was born out of an organ company's need to replace a $4 switch with a 30 cent potentiometer. The resulting device's ability to shape tone by sweeping through frequencies with a pedal operated pot immediately inspired all who heard it. The vocal quality brought to mind the Harmon mute style of trumpet playing, in particular the blowing on Clyde McCoy's "Wah Wah Trumpet". Thus you will see Clyde McCoy's name on the bottom of early wah wah units, as the term was dutifully licensed from him!