Who said "Heard melodies are sweet, but those unheard are sweeter."?

This quote is attributed to John Keats.

Heard melodies are sweet, but those unheard are sweeter. - John Keats

"Heard melodies are sweet, but those unheard are sweeter."

John Keats Music

Poet English 1795–1821

"A thing of beauty is a joy forever"

"The poetry of the earth is never dead"

"I am certain of nothing but the holiness of the heart's affections"

"Negative capability is when a man is capable of being in uncertainties without irritably reaching for fact"

"Music is the language of the soul."

"My music comes from my heart."

"Music transcends all language barriers."

"Music is the universal language of love."