I Know Why The Caged Bird Sings...?

Just finished reading Maya Angelou's book mentioned above.
If any of you have read it, please tell me why the caged bird sings. I still don't know after reading her manuscript cover to cover.

I looked up the poem, Jabber, as I had not ever read it. Apparently the bird sings for want of freedom.

I tried to print out the poem, but it won't show up. So here is a link to read it.

I didn't know there was a poem; I thought there was only a book. Thanks Anne.

I read the poem but that brought about questions:

Do all caged birds have clipped wings?
And it doesn't seem that all caged birds have their feet tied.

But I'm glad to know they sing of freedom; for that question didn't seem to be satisfied from reading the book.

I'd not read the poem or the book, Jabber. So at least I've now read one...