Long Indeed and VERY well executed.
This is a magnificent piece of work. I personally think this is better than anything Samuel Hazo has ever written (but that's more or less a preference). I dare not let this be over looked. It's a great ballad piece that would probably get the hell trimmed out of it for marching band (since that is the practicality of its sound). I would use the keyboards for more counterpoint than melody, but that's a personal choice. They do add counterpoint here and there, but as a whole, they generally add a lot of counterpoint and rhythms. The abrupt ending confuses me. There's no noticable build up other than complexity. Dynamically, it's only a little louder than the beginning. There's too many chord changes leading up to the end. After a massive cut off after a long, loud final chord, play a little more of the melody from the beginning as a tie in, and end the piece with a low tonic chord. That's just my humble ranting from what I've seen done in marching band and drum corps. I miss cymbal work too. I would have cymbal work out the wazoo with a slow piece, especially for builds.
Now, this is a great piece in and of itself. The above are just thoughts to consider. The simplicity of the melody and harmony and the tension keep me listening. I think you have done really well with this piece and wish you the best in the future.
i think its long enough but you do have to add countermelody and bass instruments to the the body of the piece which it sounds like starts just after the beginning