ZIEGFELD The Man Who Invented Show Business By Ethan Mordden St. Martin's. 335 pp. $32.95 "Flo liked his erotica neat and fulfilled, not coy and gibbering," Ethan Mordden writes close to the beginning of this engaging, often gnomic, information-packed biography of Florenz Ziegfeld. Further on, describing the Broadway that the flamboyant manager-producer set out to conquer, the author writes that "fancy restaurants catering to those oathed to leisure and the breaking of sumptuary laws were already in place, as infrastructure of the late-night ... (more)