Displaying a whole GrandStaff system if only one of its staves is alive

In many orchestral scores it is custom to not show staves for instruments that are silent for a while; this is called a ‘Frenched’ score. LilyPond provides this functionality via the \RemoveEmptyStaves command.

When they play again it is often preferred to show the staves of all instruments of such a group. This can be done by adding the Keep_alive_together_engraver to the grouping context (e.g., GrandStaff or StaffGroup).

In the example below the violins are silent in the second system. Only the first violin plays the last measure in the third system but the staff of the second violin is also displayed.

\version "2.24"

\score {
  <<
    \new Staff = "Staff_flute" \with {
      instrumentName = "Flute" 
      shortInstrumentName = "Fl"
    } \relative c' { 
      \repeat unfold 3 { c'4 c c c | c c c c | c c c c | \break }
    }

    \new StaffGroup = "StaffGroup_Strings" <<
      \new GrandStaff = "GrandStaff_violins" <<
        \new Staff = "StaffViolinI" \with { 
          instrumentName = "Violin I" 
          shortInstrumentName = "Vi I"
        } \relative c'' {
          a1 | R1*7 | \repeat unfold 12 a16 a4 |
        }
        \new Staff = "StaffViolinII" \with { 
          instrumentName = "Violin II" 
          shortInstrumentName = "Vi II"
        } \relative c' {
          e1 | R1*8 |
        }
      >>

      \new Staff = "Staff_cello" \with { 
        instrumentName = "Cello" 
        shortInstrumentName = "Ce"
      } \relative c {
        \clef bass \repeat unfold 9 { c1 } |
      }
    >>
  >>
}

\layout {
  indent = 3.0\cm
  short-indent = 1.5\cm

  \context {
    \GrandStaff
    \consists Keep_alive_together_engraver
  }
  \context {
    \Staff
    \RemoveEmptyStaves
  }
}