Have you ever heard a song and wondered, “What’s that cool “wacka wacka” sound?” Well wonder no more! That sound you hear is called a “wah” pedal. From Zappa to Hendrix, and Gilmour to Hayes, the wah pedal has become, and always will be, a staple in music history. Put simply, a wah pedal is a type of filter. There are two standard types of audio filters: low pass filters that allow low frequencies passed a set frequency cut-off point, filtering out high frequencies, while high-pass filters are the opposite, letting high frequencies past the cut-off frequency filtering out low frequencies.

Trumpeter Clyde McCoy who helped popularize the first wah pedal

Officially coined in the 1960s by the Thomas Organ Company, the pedal known as the “wah”, is an effects pedal that alters tone, creating a sound that many feel assimilates the human voice or a baby “crying.” In the early 1920’s, trumpet player Clyde McCoy discovered that by moving a mute in and out of his instrument’s bell, a pleasing “cry-like” tone was able to be produced, a discovery leading to the inevitable creation of the “wah pedal” in 1966. Stemming from a re-design of a popular amplifier at the time, The Thomas Organ Company joined forces with Jennings Musical Instruments (VOX) to promote the first official wah pedal housed within a VOX Continental Organ volume pedal. Already a popularized brand, VOX effortlessly helped promote the patent created for the Wah pedal, the patent of which was officially submitted by the Thomas Organ Company in 1967. In the years to follow, the wah pedal would become a catalyst for musical inspiration and creation.

Original VOX Clyde McCoy wah pedal

While the wah pedals initial introduction was by and large a recreation of McCoy’s ideas, Brad Plunkett, a junior engineer, was commissioned by The Thomas Organ Company to redesign a Vox amplifier with a less-expensive configuration that provided an “equally pleasing” tone in the later 1960s. By lifting a bread-boarded transistorized tone circuit from the Thomas Organ, Plunkett was able to duplicate VOX’s 3 position circuit. Astounded by what he heard, Plunkett showed his findings to fellow “wah-effect” inventors and pioneers, Bill Page and Del Casher. By connecting this new “Frankenstein” circuitry output into a speaker, he introduced Casher, Page, and eventually, the rest of the world, a sound that would inevitably change the way people both listened to, and created music.

Together, Casher, Page, and Plunkett created a prototype for the first official wah pedal ever created. Although it was originally an idea that stemmed from the tonal manipulation of horned instruments such as trumpets and saxophones, Casher heard the sound and insisted that this was a tone more “appropriate” for a guitar. Casher suggested his idea to Joe Banaron, CEO of Thomas Organ Company, which as result permitted Casher to plug the first electric guitar into the prototype wah pedal.

An original “Cry Baby” wah pedal made in Italy

Being that Joe Banaron (CEO of the Thomas Organ Company) was a big fan of big band music, his initial intentions were to market the pedal for wind instruments. However, after hearing Casher’s ideas, the company decided to use Clyde McCoy’s name to endorse their new idea now marketed toward guitarists. Prior to this decision, Plunkett and Casher teamed up to modify the wah pedal to better accommodate the tonal and harmonic qualities of the guitar. Soon after, the Thomas Organ Company decided to brand their product, naming it the “Cry Baby” without ever having put a trademark on the name. As a result, the market became flooded with imitation pedals and other copy-cats using the “Cry Baby” name to distribute it. Even so, some of rock histories best guitarist adopted the Wah pedal with great accord. Jimi Hendrix and David Gilmour, among the many, are two of the most famed musicians to have popularized the Wah effect: Gilmour with his “trippy”, yet smoothly dark tones, Jimi with his psychedelic, blues rock riffs. Without McCoy’s ingenuity, passion, creativity, and help from a few others, the wah pedal would have perhaps, never been invented.

Shaft soundtrack featuring music by Isaac Hayes

One of the most popularized portrayals of the wah pedals application can be heard in the Shaft theme song. The Shaft theme song was written and recorded by Isaac Hayes in 1971 and is the soulful and very funky theme song you hear as the rolling intro to the movie “Shaft.” Gaining much popularity and even earning the number two spot on the Top Billboard Soul singles chart, the theme song effortlessly catapulted the Wah pedal to further heights and popularity in the 1970s. As a result, Isaac Hayes became the first African American to win an Academy Award for best original song.

Morley Steve Vai Signature Bad Horsie 2 wah pedal

Moving forward with continued innovations, we have Morley. Unlike the circuitry involved in creating the original wah pedal from VOX and Dunlop, Morley pedals use an electro-optical circuitry rather than a potentiometer to control the effect. The advantage? A light dependent and more reliable resistor that will never wear out or become “scratchy” over time due to a potentiometer in its signal path. The Morley pedal company originated in the 1960s by brother Raymond and Marvin Lubow. According to the Morley Pedal company in addition to rocking the pedal up and down to crest a spectral glide, another function of the wah pedal is to use it in a fixed position. A guitarist using the wah in this way selects a position on the wah pedal and leaves the pedal there. Depending on the position of the pedal, this will boost or cut a specific frequency. A popular use for this feature is emphasizing the “sweet spot” in the tonal spectrum of a particular instrument.

Dunlop EVH95 Eddie Van Halen Signature Wah Guitar Effects Pedal

While some of the most famous electric guitarists of the time were keen to adopt the wah pedal soon after its release, it was Dunlop that “raised the bar” by introducing what many today would argue as the most popular wah pedal ever, the “Cry-Baby.” Due to their failure to trademark its name, the Thomas Organ Company’s cry-baby fell to the wayside amidst Dunlop’s more popular version of the cry-baby, the GCB95 Cry Baby. From 1966 until sometime in 2003 this pedal was produced with a black inductor, which is still available as a spare part from Dunlop. Dunlop began using the red Fasel inductor in this pedal in 2003, an alteration of an electrical component in the wah pedals original design that many feel offers a more “natural” and deeply voiced “vintage” tone. According to its founder Jim Dunlop, the GCB95 “faithfully represents the tone and spirit of the very first model…using a component called a Halo Inductor to give the original Clyde McCoy pedals their highly coveted smooth vocal quality.” Several re-releases of the classic model have since been made, offering it with gold hardware, in smaller sizes, or including European or Japanese made parts. Several “artist editions” of the wah pedal have also been released by Dunlop, such as the JHM9 Jimi Hendrix, the JP95 John Petrucci, the SC95 Slash, the EVH95 Eddie Van Halen, and many more. Some include the famous Jimi Hendrix Cry Baby, also releasing a Fuzz Wah effect, Hendrix is perhaps the most famous musician to have popularly used the wah pedal in such way that music had never seen.

To this day, the wah pedal keeps its widespread use among guitar players. It had a lot of alterations from many manufacturers in the form of Bass Wah, Auto-wah, and other interesting takes but the original sound is still sought after. What many musicians soon found unique and irresistible of the wah pedal is that it allowed the guitarist an extra facet of expression. Unlike many effects, which are switched on, and forgotten about, the wah can be played like an extension of the instrument. The wailing sound of solo guitars and the ‘wacka wacka’ rhythm will undoubtedly remain a staple in future recordings by musicians who have yet to discover its glory.