(pclose (ly:font-get-glyph fn "accidentals.rightparen"))
(popen (ly:font-get-glyph fn "accidentals.leftparen"))
(subject (callback grob))
; remember old size
(pclose (ly:font-get-glyph fn "accidentals.rightparen"))
(popen (ly:font-get-glyph fn "accidentals.leftparen"))
(subject (callback grob))
; remember old size