%slashedacciaccworkaround.ly

\version "2.22.1"

% WORKAROUND FOR A SLASHED ACCIACCATURA
% Uses (mostly) 7/4 virtual bars (invisible bar lines in the ly file)

\score {
\new PianoStaff 

<<
  \new Staff = "up" \with { 
     \remove "Time_signature_engraver"
     \override TupletBracket.bracket-visibility = ##t
     \clef treble
     midiInstrument = #"acoustic grand"
  }

  {  
    % Bar 9 (7/4) - big problem with 'keep-alive' -- see LH part
    <d'' a'' es'''!>1\p s8
    % 7-note Change staff passage
    \override NoteHead.font-size = #-3
    \once \override Beam.positions = #'(-4.0 . -4.0)
    \once \override TextScript.extra-offset = #'(-0.5 . -2.5)
    \stemDown fis''!8_\markup{\dynamic f \italic{secco}}[  
    \change Staff = "down" \stemUp c''8 
    \change Staff = "up" \stemDown e'' 
    \change Staff = "down" \stemUp f' 
    \change Staff = "up" \stemDown b'' 
    \change Staff = "down" \stemUp a'
    \change Staff = "up" \stemDown g''] ~ g''4 \bar ""
     
    % Bar 10
    \revert NoteHead.font-size
    \stemNeutral
  }
  
  %LOWER STAFF
  \new Staff = "down" \with {
     \remove "Time_signature_engraver"
     \override TupletBracket.bracket-visibility = ##t
  }
   
  {
    \set Staff.pedalSustainStyle = #'mixed
    % Bar 9 (2/4 + s8 + 5/4)
    << { g'1 \once \override TextScript.extra-offset = #'(2.5 . 4.0) s8^\markup{\draw-line #'(-2.5 . 4.0)}} 
    \\
    {des'8\sustainOn_( bes4 des'8 ~ des'8[ bes] ~ bes4_) s8\sustainOff}
    >>
    s2. s8 r4
    \bar ""
  }
 >>
 }