When sung to a rock beat the Lorca sonnet resolves into almost perfect iambics, even it involves changing the accentuation of the words in the first part of the line. The musical rhythm runs roughshod over the words.
en UN e NO che CER de RUI se ÑO REEEES
instead of of "en un anochecer de ruiseÑO res"
en E ter NO mon TÓN de DU ro TRI GOOOO
en eTERno monTÓN de DUro TRIgo.
Nevertheless I like the song a lot.