-ADD_ACKNOWLEDGER (Note_spacing_engraver, note_column);
-ADD_ACKNOWLEDGER (Note_spacing_engraver, rhythmic_grob);
+
+void
+Note_spacing_engraver::boot ()
+{
+ ADD_ACKNOWLEDGER (Note_spacing_engraver, note_column);
+ ADD_ACKNOWLEDGER (Note_spacing_engraver, rhythmic_grob);
+}