Nowadays, poems need no longer establish a solid melody before improvising. Some set a foundation by alluding to the canon or genre, others don't even try. Where there is no primary meaning, significance is distributed. The poem loses its surface, its graduations of depth. The allusions more prop up than dangle from the poem.
Attention is diffused.
In semantic memory, each concept is connected to a number of other concepts. Activating one concept activates its adjacent concepts which in turn activate their adjacent concepts. Thus, activation spreads through the memory structure, determining what is to be added and what is to be removed from the interpretation of text. This process continues until further activation of adjacent propositions does not change the propositions used to interpret the text. Alternatively, the text alluded to may not so much extend the original text as help create a new third entity.