As a teacher and musician, Lucy Warner knows the true superheroes of music do not necessarily perform on stages at rock concerts, but instead are the composers of the classical canon. That's why Lucy introduces young listeners to Beethoven, Mozart, Bach, and others in her book "Zap! Boom! Pow! Superheroes of Music." Meet the author at Bank Street Book Store on Saturday, April 8 at 10:30 a.m.