ADD_ACKNOWLEDGER (Accidental_engraver, arpeggio);
ADD_ACKNOWLEDGER (Accidental_engraver, finger);
ADD_ACKNOWLEDGER (Accidental_engraver, rhythmic_head);
ADD_ACKNOWLEDGER (Accidental_engraver, arpeggio);
ADD_ACKNOWLEDGER (Accidental_engraver, finger);
ADD_ACKNOWLEDGER (Accidental_engraver, rhythmic_head);