why maya angelou tittle the I KNOW WHY THE CAGED BIRDS SINGS

When selecting a title, Angelou turned to Paul Laurence Dunbar, an African-American poet whose works she had admired for years. Jazz vocalist and civil rights activist Abbey Lincoln suggested the title.[18] With Shakespeare, Angelou has credited Dunbar with forming her "writing ambition".[19] The title of the book comes from the third stanza of his poem "Sympathy":[20]

I know why the caged bird sings, ah me,

When his wing is bruised and his bosom sore,

When he beats his bars and 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.[21]

This is the third stanza of a poem by Paul Laurence Dunbar, a poet whom Angelou admired greatly. The poem is entitle "Sympathy."