When Lupe Lopez struts through the doors of Hector P. Garcia Elementary in sunglasses with two taped-up Number 2 pencils--drumsticks, of course--poking from her pocket, her confidence is off the charts. All day, Lupe drums on desks, tables, and chairs while Ms. Quintanilla reminds her of school rules. Lupe has her own rules: 1) Don't listen to anyone. 2) Make lots of noise. Rataplan! 3) Have fans, not friends. But with her new teacher less than starstruck,...