Ken
You speak of Debussy, Bartok etc., in the same level as Glass in the sense that they are all 'modern' as opposed to, I guess Mahler or Beethiven who are 'old fashioned.' While I disagree with this categorization (Beethoven is more modern than any in some of his works....take the grosse fugue for example)....I would question a grouping Glass with Bartok or Debussy.
Here is a simple test. Show me one work of Glass that is 'old fashioned.' Can he write a competent work in tradional harmony? Debussy ravel Bartok all showed many times they can write masterful tonal works. I doubt Glass can do that. But you can prove me wrong. A composer who can't show mastery in the foundations of the form is not a composer to me at all. The best analogy I can give is in painting...Picasso could paint in every genre before he broke tradition.
I suggest that 'minimalism' has been exploited as a way to hide behind lack of knowledge or skill. Minimalism should not mean minimal knowledge!
If you truly want modern, how about Ligeti as William mentioned? He truly creates incredible soundscapes, I've even heard the sound of tearing paper blended with the orchestra.
To me there is only high quality art or mediocre art. I don't care about modern or old fashioned.
Anand
I agree completely. You put it very well.