Concerning your question about "Ode on a Grecian Urn," I can't summarize a poem of this length stanza by stanza in this format and do it justice. The enotes Study Guide on the poem does give a brief summary that might be of help.
In "Ode on a Grecian Urn," the speaker observes a relic of ancient Greek civilization, an urn painted with two scenes from Greek life. The first scene depicts musicians and lovers in a setting of rustic beauty. The speaker attempts to identify with the characters because to him they represent the timeless perfection only art can capture. Unlike life, which in Keats's "Ode to a Nightingale" is characterized by "the weariness, the fever, and the fret" brought on by humans' awareness of their own passing, the urn's characters are frozen in time. The lovers will always love, though they will never consummate their desire. The musicians will always play beneath trees that will never lose their leaves.
The speaker admires this state of existence, but in the end it leaves his "heart high-sorrowful." This is because the urn, while beautiful and seemingly eternal, is not life. The lovers, while forever young and happy in the chase, can never engage in the act of fertility that is the basis of life, and the tunes, while beautiful in the abstract, do not play to the "sensual ear" and are in fact "of no tone." Filled with dualities—time and timelessness, silence and sound, the static and the eternal—the urn in the end is a riddle that has "teased" the speaker into believing that beauty is truth. In life, however, beauty is not necessarily truth, and the urn's message is one appropriate only in the rarefied, timeless world of art.
Keats, then, ruminates or meditates on the work or art and at first idealizes it. But the object is, after all, a work of art, not reality, and this cuts both ways. The figures in the work of art are never able to, if you will, finish what they start. And beauty is only truth and truth, beauty in works of art, not in reality.
Some engraved pictures, as, the musician, a bold lover and the lady love, the mysterious priest, a heifer, some village folks and some pastoral scenery sculptured upon the urn, -evoke the poet’s imagination. All these are the “silent form” of Attic age and they tease us out of thought as our thought of eternity.
The poet in an askance note begins to question what they are and what their reality is. The poet continues to ask –
What men gods are these? What maidens loth? What mad pursuit? What struggle to escape? What pipes and timbrels? What wild ecstasy?
On the basis of these questions, the poet begins to explain the significance of those things engraved on the urn and gives a sharp contrast between these things and the reality of life. Life is very transient. Here nothing is ever lasting. Here beauty can not keep her lustrous eyes, youth grows pale and dies. Time absorbs everything on life. We grow consumpted and decayed with the Time. The youth, the beauty, the glory, -are all to be decayed.
Once again, in the short span of our life, we have sorrows and leaden-eyed despair. Here men sit and hear each other groan. In the dreary intercourse if daily life man gets nothing but the weariness, the fever and fret. This fever of this world hangs upon the beating of man’s heart.
But the world of art is above this fever and fret of this world. Here beauty is permanence and she always keeps her luster. Everything is fair in the world of art. The fact behind this is that art absorbs Time as if art grows with the time: -
“Thou foster-child of silence and slow-time”.
The bold lover would always remain young and the lady-love would ever be charming and fair. Because they have not consumpted love. The fulfillment of love is sign of decay. So, the poet says:-
“She can not fade, though than thou hast not thy bliss
For ever wilt thou love, she be fair. ”
Again, the happy melodist would ever remain unwearied. And the mysterious priest and his followers would never be able to return their native place. Because art has captivated them.
Again, the fever of the world has no hand to touch the artistic beauty of the urn. The world of art is far above “all breathing human passion” and there is no “burning fore head” and “parching tongue” in the world of art.: -
“All breathing human passion far above,
That leaves a heart high sorrowful and cloyed.
A burning fore head and a parching tongue”
Hence, everything in the world of art is ever new, ever warm. There is no change in the world of art.