The wah-wah pedal isn’t just an electric guitar effect, it’s a peacemaker, famous MC5 guitarist Wayne Kramer tells Wax Poetics in an extended oral history of the device:
“I partnered with Billy Bragg this year in a nonprofit initiative called Jail Guitar Doors. What we do is provide instruments for those who work with prisoner rehabilitation to use music as a meditative process to learn the discipline of writing a song, to express yourself in a new and nonconfrontational way, a way to express deep feelings positively. I think it’s a very powerful tool in building self-worth. I’ve been to prison, and I know how it feels to be there. ...
“I see the wah-wah as a tool that the electric guitarist uses, and it evokes a certain familiarity. When you use it in a certain way, with traditional chords and rhythm structures, people identify with it. I’ll tell you, when I was in prison, I played in the prison band. You know I’m not a gangster, and I’m not a killer, but I got respect in prison because of the wah-wah. I remember one day, a couple of gangsters came by my house, and they looked in, and they said, ‘Oh yeah, you the white boy that plays the wah-wah. Yeah, you all right.’ (laughs) There’s an identification with the wah-wah; it’s a cultural touchstone.”
Well, for some it is. One other great quote in the story comes from wah-wah inventor Del Casher, who eagerly demonstrated his new creation for James Brown:
“I said, ‘James, this is the hottest thing. Man, you’re going to love this.’ I played it for him. And he looked at me, and he says, ‘But Del, why do you want the guitar to go wah?’ ”
Source: Wax Poetics (article not available online)