Themes of tragedy and comedy are classic tropes in writing fiction and poetry. Edgar Allen Poe's "The Raven" shows both.
The narrator is prone to fits of imagination, speaking with manners to the unseen tapping:
Presently my soul grew stronger; hesitating then no longer,
"Sir," said I, "or Madam, truly your forgiveness I implore;
But the fact is I was napping, and so gently you came rapping,
And so faintly you came tapping, tapping at my chamber door,
That I scarce was sure I heard you"--here I opened wide the door;--
Darkness there, and nothing more.
This mannerly state is contrasted with the raven itself, which, while "stately," comes in and sits on the narrator's statue:
Perched upon a bust of Pallas just above my chamber door--
Perched, and sat, and nothing more.
Then this ebony bird beguiling my sad fancy into smiling,
By the grave and stern decorum of the countenance it wore.
His dark mood is lightened by the Raven, which, being a bird, has only one expression. For a few stanzas, the narrator is not as dour as earlier, even repeating his claim as he sits to contemplate the Raven:
But the Raven still beguiling my sad fancy into smiling,
Straight I wheeled a cushioned seat in front of bird and bust and door;
Then, upon the velvet sinking, I betook myself to linking
Fancy unto fancy, thinking what this ominous bird of yore--
However, despite his "smiling," the narrator still questions the Raven and its motives:
Till I scarcely more than muttered, "other friends have flown before--
On the morrow he will leave me, as my hopes have flown before."
Then the bird said, "Nevermore."
(All Quotes: Poe, "The Raven," eNotes eText)
Had he continued to study the bird, instead of engaging it in conversation (a conversation that can have only one outcome, since the Raven only speaks one word) he might have continued his "smiling," to wash away his depression. However, the narrator is unable to think of other things, and with his self-focus on tragedy, assigns meaning to the Raven, which is, after all, just a bird.