There's an interesting article this morning in the NY Times on the man who invented the wah wah pedal...that effect sound control for the guitar with the unmistakable sound. With a flip of a knob, Del Casher heard the future...
But there is one accomplishment that Mr. Casher, now 73, wishes more people knew about: his role in the invention of the wah-wah pedal." Continued here.
Here is the demo record mentioned in the article:
And here, The Electric Prunes endorse the Vox Wah Wah: