Bow-chicka-bow-wow: What instrument does this?

You know the sound. That lusty, cheap-70’s-porn-film-sound, imitated (and ridiculed) by many. I believe it was used in the song for Shaft.

What instrument is used to make this sound? Or do people do it vocally?

It can’t be guitar. Can it? If so, what type? And can I reproduce the sound without buying any extra equipment? I have FruityLoops 3, an acoustic guitar, and a bass.

With my friend, we’re going to be doing a song called “Busted Balls” that starts out with this type of sound and suddenly shifts to driving, heavy electric guitar (using the same melody.)

A Wah Wah or Crybaby guitar effects pedal.

More about the wah wah pedal than you probably want to know

A sample

Note: “Cry Baby” is actually a brand of wah-wah pedal, made by the Dunlop company.

And the secret to the “bow chicka” sound is muting the strings while strumming and pumping the wah-wah.

Think intro to “Voodoo Chile” by Hendrix for a more rock-oriented use of the same thing. You should be able to pick up a Crybaby for fairly cheap on eBay. I got mine for $40. They’re not the greatest wah pedals on the market, but they’re more than serviceable. Get two and rig them up opposite of each other. I believe that’s what SRV used to do with his.