Here is the poem that inspired the title to Maya Angelou's book, I Know Why The Caged Bird Sings. It is the line taken from the third stanza from the poem Sympathy by Paul Laurence Dunbar (see here for the complete works). The poem is about that feeling of freedom, or lack of. When I think about the weather, my work, where I am, where I hope to be, then yes certainly, I know why the caged bird sings.
SYMPATHY
I know what the caged bird feels, alas!
When the sun is bright on the upland slopes;
When the wind stirs soft through the springing grass,And the river flows like a stream of glass;
When the first bird sings and the first bud opes,
And the faint perfume from its chalice steals—
I know what the caged bird feels!
I know why the caged bird beats his wing
Till its blood is red on the cruel bars;
For he must fly back to his perch and cling
When he fain would be on the bough a-swing;
And a pain still throbs in the old, old scars
And they pulse again with a keener sting—
I know why he beats his wing!
I know why the caged bird sings, ah me,
When his wing is bruised and his bosom sore,—
When he beats his bars and he would be free;
It is not a carol of joy or glee,
But a prayer that he sends from his heart's deep core,
But a plea, that upward to Heaven he flings—
I know why the caged bird sings!
Graphic source: Tagged
