``If you wanted a poem,`` wrote Gwendolyn Brooks, ``you only had to look out of a window. There was material always, walking or running, fighting or screaming or singing.`` From the life of Chicagos South Side she made a forceful and passionate poetry that fused Modernist aesthetics with African-American cultural tradition, a poetry that registered the life of the streets and the upheavals of the 20th century. Starting with A Street in Bronzeville (1945), her epoch-making debut volume, The Essential Gwendolyn Brooks traces the full arc of her career in all its ambitious scope and unexpected stylistic shifts. ``Her formal range,`` writes editor Elizabeth Alexander, ``is most impressive, as she experiments with sonnets, ballads, spirituals, blues, full and off-rhymes. She is nothing short of a technical virtuoso.`` That technical virtuosity was matched by a restless curiosity about the life around her in all its explosive variety. By turns compassionate, angry, satiric, and psychologically penetrating, Gwendolyn Brookss poetry retains its power to move and surprise.