The caged bird is singing of freedom and hope. 'Things unknown' refers to the fact that the bird has never enjoyed freedom before and so has no idea as to what it tastes like. Though he is singing of freedom that he has longed for all his life, it is something completely unknown to him.

Why do caged birds sing?

I Know Why the Caged Bird Sings is a 1969 autobiography describing the early years of American writer and poet Maya Angelou. ... Angelou uses her autobiography to explore subjects such as identity, rape, racism, and literacy. She also writes in new ways about women's lives in a male-dominated society.

What does the singing represent in Caged Bird?

The bird represents freedom or desire to be free, while the cage symbolizes confinement or oppression. Even the act of singing shines a spotlight on the author's ability to grow and flourish despite her challenges.