- ADD_LISTENER (Beam_engraver, beam);
- ADD_ACKNOWLEDGER (Beam_engraver, stem);
- ADD_ACKNOWLEDGER (Beam_engraver, rest);
+ ADD_LISTENER (Grace_beam_engraver, beam);
+ ADD_ACKNOWLEDGER (Grace_beam_engraver, stem);
+ ADD_ACKNOWLEDGER (Grace_beam_engraver, rest);