I think this quote from John Summers sums it up well:
"When you put a horn in a student's hands, you've taken him off the street for four hours," Tiller said. "And when he's done (with rehearsal), he's so tired that he's going home and going to sleep. If every band has 100 kids, and you've got 15 high schools, that's 1,500 kids off the street.
"We're not just making music. We're saving kids."