Modern music-especially American music, with its tendency to invite various traditions to share the same compositional space-can be a generous art, an art which welcomes inclusivity. Here are works by John Cage (b 1912), Yehudi Wyner (b 1929), John Harbison (b 1938), and Stephen Hartke (b 1952)-four American composers from different generations with different sensibilities, representing very different approaches to writing for the violin. Yet however much these works represent various facets of …