What a wonderful opening. OK, you have my attention.
You are clearly a composer who knows his way around the orchestra, and you apparently have amassed some experience. Some very colourful orchestration here, without calling for too much superfluously. I like the use of percussion, and the very nice trumpet solos...too rare.
I have to say that this may not have a specific key, but it is hardly atonal, nor is it particularly experimental. I might suggest that it belongs in the Orchestral category...perhaps even Major Works. I would definitely agree that this piece has a mind of its own...it doesn't light on any one idea for very long, yet somehow that is a strength, rather than a weakness. Your shifts and contrasts between tonalities and colours are striking...sudden at times, but not jarring at all. The music sounds "filmy" (for lack of a better term) only here and there, certainly not enough to be obviously program music for film.
Wow...not the ending I was expecting at all, but very satisfying nonetheless. I'm sorry I can't be more specific in my commentary (I'm a form-junkie, and I'm a bit at a loss with something so free), but exceedingly well done and enjoyable. My sincere compliments!
What are your influences? I'm hearing nods in the direction of Gustav Holst and his English contemporaries like Finzi...but not Vaugan-Williams. Also, what's your background? How long have you been doing this?
I recommend this piece to anyone considering the mp3 download...it's worth it! Enjoy.