Yesterday I attended a concert on campus. There’s a shy girl in one of my writing classes who came to me, ticket in hand, and asked me if I would come and see her sing. She’s a nice kid, and a diligent student, so how could I refuse? Well, it turned out to be a cappella music concert. You know, where vocal groups sing without instrumental accompaniment (aside from a little beatbox work by some of the guys in the ensembles, and that’s still not really instrumental). Now, it may seem strange to those of you who think of groups …