"Void Studies," " "Rachel Boast's extraordinary new collection, realizes a project that the French Symbolist poet Arthur Rimbaud had proposed, but never written. "Etudes neantes "was to consist of poems written as musical etudes; these would not convey any direct message but instead summon the abstract spirit of their subject. This "impossible project" has been completed by Boast in the most astonishing way, and in doing so she has increased the expressive possibilities of poetry itself. These tone poems are indeed works of pure music but despite their esoteric nature are by no means...