Birdsong is typically associated with peaceful, hopeful, or joyful things. Throughout literature it is used to symbolize the coming dawn or spring, marriage unions, and the end of hardship. However, it can also represent the pain in the lack of freedom. The “caged bird's” singing takes on heartbreaking connotations and invokes not only pity in the reader but indignation at the creature’s trapped condition.
Birds are a universal symbol of freedom. However, throughout literature they have typically been depicted as fragile or delicate and associated with women. Here, the “littleness” of the bird suggests that this creature is being persecuted in some way. It immediately makes readers sympathize with this frail creature, creating a helpless tone that should cause outrage at the speaker's plight.
While the word “fields” technically refers to land on the earth, it can be used to symbolically represent wide, open expanses. The phrase “fields of air” describes the freedom and endless possibilities that the speaker enjoyed prior to her imprisonment.
