I'm trying with a custom \hide command, defined as follows:
hide = {
\override NoteHead #'transparent = ##t
\override Stem #'transparent = ##t
\override TupletBracket #'bracket-visibility = ##f
\override TupletNumber #'stencil = ##f
\override Accidental #'transparent = ##t
\override Tie #'transparent = ##t
\override Slur #'transparent = ##t
\override Dots #'transparent = ##t
\override Staff.LedgerLineSpanner #'transparent = ##t
\override Beam #'transparent = ##t
\override Rest #'transparent = ##t
}
but with it I'm still having fermata and courtesy accidentals.
Idea how to override them to be also transparent ?