Coach Milt Brundage, physical-education teacher at Hutchinson Middle School, derives pleasure from forcing pre-adolescents to dance on command, it was revealed Monday. 'Oh, to make the children dance,' the 58-year-old Brundage said. 'To play 'Alley Cat' for hours on end, sternly admonishing those who fall behind so that they must speed themselves, it is my greatest joy in life.' Brundage has warned students in his second-period gym class that he will extend their social-dance unit another two weeks if they do not begin to show an acceptable level of enthusiasm. 'Dance! Dance for my amusement!' he told the gawky, forlorn seventh-graders. 