Chris Soucy ain't Jack Black. But as head man at a new local franchise of the alternative music school made famous by the movie, he does aim to instill youngsters with the collaborative rock-band ethic. Geared toward young musicians ages seven to eighteen, the school's program includes private lessons and group rehearsals focusing on the kind of music that students' parents probably grew up listening to; each session culminates with a live show at a local club. A week-long boot-camp version of the format will be offered this summer. You're never too young to have a professional outlook on what you do, so go, go, go, Johnny, go.