Wow, this takes me back. A good idea never dies. From an interview with Dr. Graper:

What do you remember of the GUIDO lessons on PLATO at Delaware?   Did you ever actually sit down and do them as a student?   You wrote about GUIDO a couple times in your stories.

They were excellent.  The software was truly masterful I thought (and still believe) because it was a perfect application of technology to a specific educational task.  I'm sure you know about it as much or more than I do: it took a truly dreadful, repetitive learning task (learning music intervals) and automated it.  I never had to take a class requiring it but began playing with it because of the videogame-aspect of it, later because I found I was able to use the skills it taught in actually hearing and writing down chords.  I know it sounds facetious but it was actually strange learning something at that University, and that was its appeal.

We're talking 1977 here!

Liz