When the Nicholas Brothers danced, uptown at the Cotton Club, downtown at the Roxy, in segregated movie theatres in the South, and dance halls across the country, audiences cheered, clapped, stomped their feet, and shouted out uncontrollably. Their exuberant style of American theatrical dance--a melding of jazz, tap, acrobatics, black vernacular dance, and witty repartee--was dazzling. Though daredevil flips, slides, and hair-raising splits made them...