\score {
  <<
    \new ChoirStaff <<
      {
        % First line - parts unison
        <<
          \new Staff { c' c' c' c'}
          \new Staff { a a a a }
        >>
        
        % Second line - high parts split
        <<
          \new ChoirStaff \with { systemStartDelimiter = #'SystemStartSquare } <<
            \new Staff { g' g' g' g' }
            \new Staff { c' c' c' c' }
          >>
          \new Staff { a a a a }
        >>

        % Third line - low parts split
        <<
          \new ChoirStaff \with { systemStartDelimiter = #'SystemStartSquare } <<
            \new Staff { g' g' g' g' }
            \new Staff { c' c' c' c' }
          >>
          \new ChoirStaff \with { systemStartDelimiter = #'SystemStartSquare } <<
            \new Staff { a a a a }
            \new Staff { f f f f }
          >>
        >>
      }
    >>

    \new PianoStaff <<
      \new Dynamics { s1 \break s1 \break s1 \break }
      \new Staff { c'4 c' c' c' | <c' g'> q q q | q q q q |}
      \new Staff { a a a a | a a a a | <f a> q q q | }
    >>
  >>

  \layout {
    \context { \Staff
      \RemoveEmptyStaves
    }
  }
}