\version "2.20.0"
\new TabStaff  { \tabFullNotation \time 2/4
g\prall ^\markup { \path #0.2 #'((curveto 0 -0.5 0 2 1.5 0)  )}
_\markup \tiny {grace mordent}
g16( a g8)
g4\prall
_\markup \tiny {regular mordent}
g16 a g8  }