Hate to derail the thread, but just out of curiosity, what do you consider to be shortcomings of Glass? His Company suite has always floored me, I feel much from it. I will definitely check out Part's music if it is a better take on the style.
For me, in general, he leaves to much to the imagination. He is content with just repeating a melody without the slightest hint of variation of any kind (Edit 1: this is, of course, incorrect. It has some variation, and sooome development.). Maybe it is a performer's fault as well, but I find it hard to believe that classical musicians will just play his (piano, specially) works in such a flat way because they want to. It must be his direction that his pieces sound so flat and uneventful. He may like to evocate something through them and thus he names them creatively but the music itself is too simple. Maybe the only variation introduced is by the performer's hand, trying to provide some little dynamics to the extremely repetitive pieces Mr Glass produces.
Even simple things needs some kind of complexity, IMO. It is how some things are used in context. Sometimes it is the speed at which certain things are played that add the complexity to the idea. Sometimes it is the chord progression itself with the rhythm which provide this complexity. No two elements in music are really independent. I think here is where Philip Glass fails for me: his often extremely simple melodies lack are set in a flat and simple background, repeating ad nauseam.
This is a little it unfair since I actually like Goatcraft's project. Maybe I am just placing Glass under the classical composer's banner so I expect something else from him. I expect the depth of thought and development that Arvo Part's music contains. Then again, even Goatcraft's music produces more development and variation. Please go listen to The Blasphemer! Goatcraft's (violent) debut is also more entertaining and full of content than Glass' piano music. I must admit, though, that the only full piano release by Glass that I've actively listened to is Metamorphosis. I got through it mostly out of duty, because I could not be more bored with the pieces repeating the same ... 8 or 10 bars for 10 times and calling it a day!