Poet, artist, composer and publisher Dick Higgins’ culminating work might be his 1987 study, Pattern Poetry: Guide to an Unknown Literature. The categories he draws up, and the drawing up of them, are as fascinating as the examples in this profusely illustrated book. Categories that replace received notions of prosody in visual terms call for new units of measure. Why replace? Because we equate poetry with verse, using the old would make the term “pattern poetry” redundant, short-circuiting its explanatory power.