In the Edward Arlington Robinson poem "Richard Cory" the tone of the narrator changes during the course of the poem. In the first stanza, the tone is admiring as he describes the physical appearance of Richard Cory.
He was a gentleman from sole to crown,
Clean favored, and imperially slim.
In the second stanza, there is a tone of surprise at the down to earth nature exemplified by Richard Cory.
And he was always quietly arrayed,
And he was always human when he talked;
Despite the low key profile of this man, the narrator's still places Richard Cory above the rest of the townspeople.
But still he fluttered pulses when he said,
'Good-morning,' and he glittered when he walked.
And the tone of the narrator becomes one that places even more distance between Cory and the citizens of the town. By using words like "king", and "grace" he sets Cory up as royalty.
And he was rich - yes, richer than a king -
And admirably schooled in every grace:
In fine, we thought that he was everything
To make us wish that we were in his place.
In the last stanza, the narrator's tone becomes one of bittered enlightenment. The poor people of the town continue to remain poor even as they work and hope for things to get better.
So on we worked, and waited for the light,
And went without the meat, and cursed the bread;
And yet his tone of enlightenment occurs when:
And Richard Cory, one calm summer night,
Went home and put a bullet through his head.
The narrator realizes two things. 1)Richard Cory was not as he appeared to everyone; and 2)Wealth did not necessarily bring happiness.
Enotes has some great resources at the following link.