-ADD_ACKNOWLEDGER (Part_combine_engraver, note_head);
-ADD_ACKNOWLEDGER (Part_combine_engraver, stem);
+void
+Part_combine_engraver::boot ()
+{
+ ADD_LISTENER (Part_combine_engraver, part_combine);
+ ADD_LISTENER (Part_combine_engraver, note);
+ ADD_ACKNOWLEDGER (Part_combine_engraver, note_head);
+ ADD_ACKNOWLEDGER (Part_combine_engraver, stem);
+}
+