ADD_ACKNOWLEDGER (Pitched_trill_engraver, note_head);
ADD_ACKNOWLEDGER (Pitched_trill_engraver, dots);
ADD_ACKNOWLEDGER (Pitched_trill_engraver, stem);
ADD_ACKNOWLEDGER (Pitched_trill_engraver, note_head);
ADD_ACKNOWLEDGER (Pitched_trill_engraver, dots);
ADD_ACKNOWLEDGER (Pitched_trill_engraver, stem);