Fifteen years ago, a handful of Microsoft employees started getting together for classical-music jam sessions. Today, the Microsoft Orchestra boasts 60 members, rehearses every Monday night (except during the summer), and performs six free concerts a year—three in the campus cafeteria and the rest at various public venues. The players—engineers, managers, and support staff—are supplemented by a handful of nonemployees. “If I need a piccolo, I need a piccolo,” says conductor James Truher, a veteran studio singer who also works as a program manager at Microsoft. Truher has doubled the group's membership in his four years on the podium, but not all of his recruitment efforts have succeeded: When he emailed trombonist Bill Gates and asked him to join, the chairman replied that his playing was too rusty.