While I agree with all of the sentiments so far expressed regarding MIDI
as very lacking in the field of reproducing classical works, I think there
is one large advantage that is being overlooked, and that is its usefulness
to the modern classical composer.  MIDI provides an emminently valuable
tool to the composer, not only allowing the composer to essentially use the
computer as an instument in and of itself, but also by providing, however
rough, an approximation of the sounds that the composer works with in more
traditional instrumentation.  An example from my own work being that I've
never played a violin in my life, yet with MIDI I can at least approximate
what my work would sound like in live performance, especially since it is
a lot easier for me to hear it in my head than if, perhaps, I had to play
it all out on the piano, or worse yet, imagine it all, and not having any
clue, really, what it might come out sounding like in the end, until the
day, if ever, it might actually be performed.

Robert Stieger
http://znufrii.homepage.com