Which poet wrote "Heard melodies are sweet, but those unheard are sweeter"?

“Heard melodies are sweet, but those unheard are sweeter” is a line from “Ode on a Grecian Urn” by John Keats. Literary experts tell us that it means that the power of our imagination is often greater than reality. It was reported that Keats believed that "imagining something could bring more happiness than having things in actual reality. Real things that people own and use often proved to be very disappointing".

Within the entire poem “Ode on a Grecian Urn”, the speaker is describing what he sees on the urn. Credible explanations highlight the contrast between the "heard melodies" and the "unheard" melodies. They link to a contrast that is established throughout the poem: the difference between the ephemeral and marred nature of human existence and the perfect state of art.

Keats (1795—1821, born in London, England) was the eldest of Thomas and Frances Jennings Keats’s four children. He only lived for 25 years and died in Rome, Italy of tuberculosis. It is said that he had perhaps the most remarkable career of any English poet. He published only 54 poems, in 3 slim volumes and a few magazines.

During his life, he took on many literary challenges. His writings involve a wide range of poetic forms. They include the sonnet, the Spenserian romance, the Miltonic epic, and others. Keats is said to have defined "anew these items with his own fusion of earnest energy, control of conflicting perspectives and forces, dry ironic wit, and poetic self-consciousness".