Turbo-charged comic Jack Black shakes School of Rock to its foundations, wailing with born-again metalhead passion as Dewey Finn, a guitarist who gets kicked out of a band because he grandstands too much--or, to put it another way, enjoys himself. Through an intercepted phone call, Finn gets a job as a substitute teacher for a fifth grade class at a private grade school. Neither students nor teacher quite know what to do with each other until Finn discovers that some of his young charges can play instruments; at once he starts turning them into a blistering rock & roll troupe that can crush his former band at an upcoming competition. School of Rock is silly and formulaic, but director Richard Linklater (Dazed and Confused), writer Mike White (The Good Girl), and especially Black and co-star Joan Cusack invest the formulas with such glee that the movie is irresistibly fun. --Bret Fetzer