\set squashedPosition = #0
\override NoteHead #'style = #'slash
\override Accidental #'stencil = ##f
+ \override AccidentalCautionary #'stencil = ##f
}
improvisationOff = {
\unset squashedPosition
\revert NoteHead #'style
\revert Accidental #'stencil
+ \revert AccidentalCautionary #'stencil
}