Writing music in trackers is like using a great programming language. A super fast way to get your thoughts into something you can listen to. I've never found a more efficient mechanism since.
Who could forget FastTracker 2! I was about 13 or 14 when I discovered it. There is something intoxicating about composing with the computer in that way. Granted, there was and are a ton of corny .mod files out there but I feel like mod tracking is where I fell in love with the aesthetics of editors and code.
Thanks so much for bringing this to attention! :)
FT2 and Impulse Tracker were amazing pieces of DOS software. Impulse Tracker somehow eventually supported DirectSound audio output when running in a Windows 98 DOS box, IIRC. IT did all of its graphics in pure text mode by reprogramming the VGA card's font table.
[1] http://en.wikipedia.org/wiki/Tracker_(music_software)
[2] http://www.youtube.com/watch?v=hjAwxG3q3Yo