Ode to a Nightingale by John Keats par excellence. It is one of the most representative of Romantic poems. It showcases almost all the features of romantic poetry.
It is a subjective and lyrical poem which is primarily about the poet's response to and interpretation of the unseen bird's song. The bird is just a stimulus for the self to begin its transcendental flight to a dreamland, but then, the mystical land of fantasy is replete with suffering and the golden pangs of tragedy still, thus marking a subjective oscillation and a return to the sordidly mortal world of reality, as charged by the crucial word "forlorn". The poem employs a synesthetic imagination, evoking all possible senses and the meditative melancholy, the temporal flux and the tragedy of the decaying beauty--all that seemed eternal, being unmade, the melody of the cadence, the emotional primacy, the humanistic assumptions, the mood of awe and wonder---all these elements contribute to the making of this classic of romantic poetry.