I think that that was great although think that there are two things that could improve it. The first is that I think that the marimba could have done more in the first (third(1/3)) part of the the composition. Secondly (and I am not clear on the requirements of the assignment but I think that it would have been a bit more interesting if you added a part for chimes in which the chimes played chords (although I guess they wouldn't really be chords if they were only one to two note at once) throughout the composition.