'Ode to a nightingale' by John Keats deals with the theme of escape more in the present - 'Ode on a Grecian Urn' on the other hand deals with escapism in the past. In the first poem, John Keats is weary of his day and imagines the cooling balm of a life following the nightingale into the deepest recesses of the spring green woodland. In the second poem, it is the past where the two young sweethearts are in a place of escape. Trapped in time while we move on, their leaves do not wither and their love does not die. We, however, and Keats, do move on and time keeps turning - the image of the young people lives forever but the real people they were based on did die, as we all do eventually. The Nightingale represents the comfort and solace for Keats in the present.

Think of these two poems as representing opposite ideas - life and death; life, because the nightingale is a living creature and death because the scene depicted on the Grecian urn no longer exists. Although life is not always like listening to the beautiful sounds of the nightingale's song and often is full of "the weariness, the fever, and the fret" brought on by fears of death, the urn's characters can no longer experience life's pain or joy because they are dead. With the urn, the poet sees that beauty can be eternal but life is not.

The links below to these two poems on eNotes can provide you with additional insights to complete your assignment.