[allthumbs]

I bought that stuff years ago in the dawn of computers. It was on audio tapes. I never got anywhere with them. The guy assumed you would always have some one available to play notes on a piano for you to work with. It was also piano based. I did see one specifically for guitar but, it completely disappeared many years ago. I am assuming it bombed. The odds are not good with those things. Relative pitch is easier and much handier to develop.
Edit. I just looked deeper into this guys stuff. Your looking at many months of hard work with his stuff. It has been my experience that few people have the dicipline to stick with something like this. 97 bucks U.S. He uses some stuff that is allready out there free on the net. If I had money to burn, I might buy it out of curiosity.