I think you are talking about the poem "The Darkling Thrush"
“The Darkling Thrush” is a poem by the English poet and novelist Thomas Hardy. The poem describes a desolate world, which the poem’s speaker takes as cause for despair and hopelessness. However, a bird (the “thrush”) bursts onto the scene, singing a beautiful and hopeful song—so hopeful that the speaker wonders whether the bird knows something that the speaker doesn’t. Written in December 1900, the poem reflects on the end of the 19th century and the state of Western civilization. The desolation of the scene the speaker sees serves as an extended metaphor for the decay of Western civilization, while the thrush is a symbol for its possible rebirth through religious faith.
