It sets quite a clear mood, of sadness, especially on the solo voice. I liked the contrast between the horn, with its soft and smooth sound, and the solo voice, with its rough, nearly-cryin' timbre. It feels very suitable for a scene that describes any type of sadness.
Here's another thing I enjoyed: the horn has a kind of indefinite ethinical figure, while the bells feel a lot 'church-like' and the solo voice, sort of oriental, arabian. This contrast leaves the atmosphere of the whole song kind of hybrid, undefined, which I find very attractive, since it's not restricted to a single ethnical structure and can be applied in several different situations.
However, I agree with what was said before, about the abruptness of the ending, and I think you could create little contrasts throughout the song that aren't really noticed separatly but create a nice variation on the whole aspect of the work. That would be a way to enrich a bit the orchestration, but it would obviously affect the work and possibly create a new, more tense mood.
Another idea that would really really make the work a lot more tense is the use of imitative couterpoint on the main theme, specially if the other brass instruments were encharged of such counterpoint. I guess it would kind of change the whole thing...anyways, just a thought!
Really liked it, thanks for posting!
Bill