Task: Text Categorization
Input (English): This poems fourth stanza mentions a green altar where a mysterious priest leads a heifer to be sacrificed. Its second stanza gives a command to "pipe to the spirit ditties of no tone" because heard melodies are sweet, but those unheard/ Are sweeter. To the fair youth beneath the trees who cannot leave her song, the "happy melodist for ever piping songs for ever new, the poet ascribes "more happy, happy love! Its opening stanza asks "what leaf-fringed legend haunts about thy shape," and refers to the title object as a sylvan historian and a still unravished bride of quietness. FTP, name this poem ending with the lines beauty is truth, truth beauty - that is all ye know on earth, and all ye need to know," an ode by John Keats.
Output (English): Literature