+ADD_ACKNOWLEDGER (Spacing_engraver, staff_spacing);
+ADD_ACKNOWLEDGER (Spacing_engraver, note_spacing);
+ADD_ACKNOWLEDGER (Spacing_engraver, rhythmic_head);
+
+ADD_TRANSLATOR (Spacing_engraver,
+ "make a SpacingSpanner and do "
+ "bookkeeping of shortest starting and playing notes ",
+
+ /* create */ "SpacingSpanner",
+ /* accept */ "",
+ /* read */
+ "currentMusicalColumn "
+ "currentCommandColumn "
+ "proportionalNotationDuration",
+
+ /* write */ "");