http://en.wikipedia.org/wiki/Max_(software)
Later that year I got my hands on a synthesizer and a copy of MAX and it became the first 'real' programming that I did. The real-time feedback made it easy to learn and debug, while its graphical nature made it highly prone to actual 'spaghetti code' unless I properly modularized everything. I quickly learned that I was a better programmer than musician - so I set up MAX to 'cybernetically enhance' my own playing.
If it wasn't for MIDI's fairly simple protocol and MAX's powerful tools built around it, I might not even be a programmer today.