Marcia B. Siegel s career as a dance writer spans the same years as Twyla Tharp s choreography. A contributing editor to the "Hudson Review" and dance critic for the "Boston Phoenix, " Siegel has been a regular reviewer for "New York" magazine, the "Christian" "Science Monitor, " and the "Soho Weekly News, " and has written for journals and periodicals in the U.S. and Europe. Biographer of modern dance pioneer Doris Humphrey and author of the classic study "The Shapes of Change: Images of American Dance, " she has also published three collections of reviews and essays. Marcia Siegel was the 20...