+
+ SCM props = get_outlet ()->get_property ("trebleStaffProperties");
+ Context *up = get_outlet ()->find_create_context (ly_symbol2scm ("Staff"),
+ "up", props);
+
+ props = get_outlet ()->get_property ("bassStaffProperties");
+ Context *down = get_outlet ()->find_create_context (ly_symbol2scm ("Staff"),
+ "down", props);
+
+ up_.set_context (up);
+ down_.set_context (down);
+
+ Context *voice = up->find_create_context (ly_symbol2scm ("Voice"),
+ "", SCM_EOL);
+ set_context (voice);
+ Music_wrapper_iterator::construct_children ();
+}
+
+void
+Auto_change_iterator::do_quit ()
+{
+ up_.set_context (0);
+ down_.set_context (0);