Group Motion--an improvisational dance performance practice--represents fifty years of co-creation by the authors, with the participation of thousands of dancers, musicians, videographers and others around the globe. Informed by Mary Wigman's expressionist dance and other contemporary dance and theater traditions, Group Motion has brought dance not only to stages worldwide, but also to public parks, prisons and airports. Part memoir, part guidebook, part philosophy of art treatise, this book provides step-by-step guidance to dozens of improvisational structures or games for dance professionals, theater artists, musicians and other performers who use movement for creative expression.