Hm while I like the poem in its entirety I think you could work on diction here. I'm an opponent of cliches, so I'd personally suggest trying to find another way to characterize and express the cage and the bird singing. To stay within your theme, you could relate your falling apart to losing feathers rather than going "piece by piece", which is an everyday saying and therefore also slightly cliched. I think you should focus on trying to create a new experience for your reader when they take on your poem rather than just write about your experiences in ways that people have hear before. Maybe this criticism is too critical--I feel like this is the most critical I've been on here. I hope I don't offend; You did a nice job with the idea, but I think you have the potential to make this piece even better.

This has a very dark feel, and the short lines and large spaces between lend it a sort of drama and heaviness. For some reason, when I think of birds in poetry, I think of Emily Dickenson's Hope Is the Thing With Feathers. This is, for me, obviously a sharp contrast to what I normally percive them as. One, the personification of hope, the other of all it means to be lost, frail and alone. I think that just makes me appreciate this a bit more, though.

Your poetry is very, very deep and slightly dark. This poem is simple but beautifuly written. I love it :D!!!!!!!