(stem-info ,pair? "caching of stem parameters")
(note-columns ,pair? "list of NoteColumn grobs.")
-;;; add-join would be enough if in Mensural_ligature::brew_ligature_primitive
+;;; add-join would be enough if in ly:mensural-ligature::brew-ligature-primitive
;;; the next note could be seen
(join-right-amount ,number? "")