appoggiatura =
#(define-music-function (music) (ly:music?)
   #{
   \grace { \temporary\override Stem.direction = #UP <>_\tweak transparent ##f _\tweak stencil #ly:slur::print _( #music \revert Stem.direction } <>) 
   #})


{\hide Slur c''( d'') \appoggiatura c'' d'' }
{\omit Slur c''( d'') \appoggiatura c'' d'' }