Explanation:
Shelley's statement "Heard melodies are sweet" is a part of his poem "Ode to a Grecian Urn". The poem is about an ancient Greek urn and its beautiful imagery. In this poem, Shelley explores the various aspects of beauty.

Beauty is heard
Shelley believes that beauty can be found in music and the sounds around us. He suggests that when we listen to music, we can experience a type of beauty that is not found in other things. The beauty of music can be heard and it can evoke strong emotions in us.

Heard melodies are sweet
Shelley's statement "Heard melodies are sweet" means that the beauty of music is sweet to the ear. The melodies that we hear can be pleasing and enjoyable. Shelley believes that music has the power to make us feel happy and uplifted.

Beauty is seen
Shelley also believes that beauty can be found in visual art. In the same poem, he writes "Beauty is truth, truth beauty, - that is all ye know on earth, and all ye need to know." This suggests that beauty can be found in the truth and goodness of things. When we see something that is true and good, it can be beautiful to us.

Beauty is Truth and Goodness
Shelley's statement "Beauty is Truth and Goodness" means that when we see something that is true and good, it can be beautiful to us. This suggests that beauty is not just about appearances, but also about the qualities that something possesses. Shelley believes that beauty can be found in things that are honest, pure, and good.

In conclusion, Shelley's statement "Heard melodies are sweet" means that beauty can be found in music and the sounds around us. It suggests that when we listen to music, we can experience a type of beauty that is not found in other things.