Poetry is an art form that demands heightened attention and retention. It both invites and rewards more intense involvement than we normally give to other kinds of speech. Poetic technique, therefore, is never esoteric but eminently practical. It serves at least two purposes. First, it announces that a poem differs from other kinds of speech, that it requires the audience's special attention. A poem begins by attracting our attention through its sound, shape, typography, syntax, texture, or tone. Second, the technique maintains the audience's involvement. All poetic form is a way of keeping the audience's attention beyond what ordinary language requires. Meter, for example, creates a gentle trance state in the auditor. Since poetry is more intense, condensed, and expressive than ordinary language, it needs these techniques to carry the burden of its message.
Dana Gioia