Further information: This was the prologue to Dylan’s Collected Poems 1934-1952.
‘I set myself, foolishly perhaps, a most difficult task: The prologue is in two verses…of 51 lines each. And the second verse rhymes backward with the first. The first and last line of the poem rhyme; the second and the last but one and so on and so on’.
(Dylan’s description of this ambitious poem).