"You know what 'Black To Comm' means?
Okay. "Black To Comm" was when we were playing the Grande Ballroom, we used to let bands - a lot of bands would use our equipment, and we would say, "Fuck you, if you break it, we told ya... "black to comm." Quite simply, on the P.A. amp, "Comm" is commonly referred to as the negative ground, and the "Black" was the wire... clear from the power source, right?
And that's exactly what it was, it's like, "Okay, just be sure you put the black wire into the comm connection here," you know what I mean? "if we trip over it and knock it out again" - because there was all these wires strewn across the stage." Full Interview Here (Dennis Thompson interviewed by Ken Shimamoto)