Choosing an instrument is only Ada's first problem: it's not easy to make the violin play sweetly; it's hard to learn to play in time; and her sister Ellen says Ada gets a double chin when she plays. But worse teasing comes from the older kids who hang out in the underpass on the way to school--they call her Ada Potato, ask whether she's got a machine gun, and even snatch at her violin case. Mama agrees that this is a problem, and tells how she once won over some children who teased her as a child. Ada successfully adapts the technique: she gets a group of fellow instrumentalists together, and they all march through the tunnel playing ""When the Saints Come Marching In"" with such enthusiasm that the menacing punks cheerfully join their parade. The author's clean, no-nonsense illustrations are exactly right for this realistic sample of peaceful defusing of the sort of situation that too often leads to adult intervention and confrontation; Ada and her friends are sturdy and unsentimentalized; the young punks and their hangout are just scary enough. Good fare for provoking discussion.