Birds are a natural symbol of freedom. For thousands of years, cultures have looked up to the sky and marveled at the freedom of birds. In modern times, birds served as inspirations for humanity’s efforts to fly, culminating in the airplane, which was modeled after birds’ bodies and wings. Birds are also a symbol of hope. Doves, for example, frequent Christian and Jewish imagery to represent holiness and sanctity. Birds fly high in the sky, presumably closer to heaven than humans.

The ability to fly anywhere whenever one wants is a popular image in music, books, and poems. Birds are a sign of freedom because they are not limited by place. Therefore, the image of a caged bird makes sense as a symbol for captivity. Caging a bird restricts its ability to use its wings and fly, thus completely taking away its freedom.

The singing in the poem applies to both birds and people. There is a long tradition of people who are in oppressive situations singing to cope with the daily struggles of their captivity. The songs of enslaved people, for example, were often songs of hope and often looked to the future. Those songs inspired future generations and influenced the development of many modern musical genres, including the blues, rock and roll, and hip-hop.