Doubling part's staves in LilyPond

Question

I am trying to typeset some music in Lilypond, where there is a player doubling on an auxiliary instrument. I would like the 2nd flute player to change to 2nd piccolo. But I also want the staves to be displayed in the right order (i.e. Picc. 1, Picc. 2, Fl. 1, Fl. 2)

---

A minimal example code is provided below which almost works, however the old staff remains even though it is empty:

I don't want to use \RemoveEmptyStaves, because there are staves (with rests) throughout the score that I do want displayed.

• Is there some other way to "kill" the old staff?

• Is there another way to write a doubling player's part on different staves?

---

Another approach that I have tried, is keeping a single staff for the doubling player (by removing/commenting-out the line marked with the asterisks *** in the code below). This is much like the example on the parts-writing page of the documentation.

I can reset staff's shortInstrumentName, but the alignBelowContext does not seem to work, so the staff doesn't move into the right place:
(resetting the midiInstrument doesn't work either)

---

Code

    \version "2.21.0"
    
    piccoloOne = {
        \new Staff = "piccolo-one" {
            \set Staff.instrumentName = "Piccolo 1"
            \set Staff.shortInstrumentName = "Picc. 1"
            \set Staff.midiInstrument = #"piccolo"
            \transposition c''
    % 1
                fis''1~ | fis''1~ | 
    % 3
                fis''1 |
        }
    }
    
    fluteOne = {
        \new Staff {
            \set Staff.instrumentName = "Flute 1"
            \set Staff.shortInstrumentName = "Fl. 1"
            \set Staff.midiInstrument = #"flute"
            \transposition c'
    % 1
                b'1~ | b'1~ |
    % 3
                b'1 |
        }
    }
    
    fluteTwoDoublingPiccoloTwo = { 
        \new Staff {
            \set Staff.instrumentName = "Flute 2"
            \set Staff.shortInstrumentName = "Fl. 2"
            \set Staff.midiInstrument = #"flute"
            \transposition c'
    % 1
                d'1 | R1^\markup{"muta in Picc. 2"} | \break
    % MUTA          
        } \new Staff { %  ***
            \set Staff.alignBelowContext = #"piccolo-one"
            \set Staff.shortInstrumentName = "Picc. 2"
            \set Staff.midiInstrument = #"piccolo"
            \transposition c''
            \once\override Staff.TimeSignature #'stencil = ##f
    % 3
                d''1~ |
        }
    }
    
    \score {
        \new StaffGroup
            <<
                \piccoloOne
                \fluteOne
                \fluteTwoDoublingPiccoloTwo
            >>
            
        \layout {
            indent = 20 
            short-indent = 10
        }
        
        \midi { }
    }

---

Update: Solution

Following the accepted answer below, the trick is:

• to use VerticalAxisGroup.remove-layer for each of the doubling part's staves,
• and the Keep_alive_together_engraver for the staff group:

Updated Code

    \version "2.21.0"
    
    piccoloOne = {
        \new Staff = "piccolo-one" {
            \set Staff.instrumentName = "Piccolo 1"
            \set Staff.shortInstrumentName = "Picc. 1"
            \set Staff.midiInstrument = #"piccolo"
            \transposition c''
    % 1
                fis''1~ | fis''1~ | 
    % 3
                fis''1 |
        }
    }
    
    fluteOne = {
        \new Staff {
            \set Staff.instrumentName = "Flute 1"
            \set Staff.shortInstrumentName = "Fl. 1"
            \set Staff.midiInstrument = #"flute"
            \transposition c'
    % 1
                b'1~ | b'1~ |
    % 3
                b'1 |
        }
    }
    
    fluteTwoDoublingPiccoloTwo = { 
        \new Staff 
        \with { \override VerticalAxisGroup.remove-layer = 2 } {
            \set Staff.instrumentName = "Flute 2"
            \set Staff.shortInstrumentName = "Fl. 2"
            \set Staff.midiInstrument = #"flute"
            \transposition c'
    % 1
                d'1 | R1^\markup{"muta in Picc. 2"} | \break
            
        } 
    % MUTA  
        \new Staff 
            \with { \override VerticalAxisGroup.remove-layer = 1 } { 
            \set Staff.alignBelowContext = #"piccolo-one"
            \set Staff.shortInstrumentName = "Picc. 2"
            \set Staff.midiInstrument = #"piccolo"
            \transposition c''
            \once\override Staff.TimeSignature #'stencil = ##f
    % 3
                d''1~ |
        }
    }
    
    \score {
        \new StaffGroup
            \with { \consists "Keep_alive_together_engraver" } {
            <<
                \piccoloOne
                \fluteOne
                \fluteTwoDoublingPiccoloTwo
            >>
        }
            
        \layout {
            indent = 20 
            short-indent = 10
        }
        
        \midi { }
    }

Answer 1

What you want is the VerticalAxisGroup.remove-layer property. You can find a code example exhibiting similar behavior to what you want at http://lilypond.org/doc/v2.23/Documentation/notation/modifying-single-staves#hiding-staves.