Concerto Grosso scores? Was: Question about condensed score

[Mats Bengtsson]

On 2023-08-14 19:46, David Kastrup wrote:
> Sounds somewhat like
>
>
> exa.ly
>
> %%%
> \version "2.24.1"
>
> global = {
>    s1\break
>    s1\break
>    s1
> }
>
> flOne = \relative c' {
>    e1
>    r1
>    e1
> }
>
> flTwo = \relative c' {
>    c1
>    r1
>    c1
> }
>
> \new StaffGroup \with { \consists "Keep_alive_together_engraver" }
>
> <<
>    \new Staff \with {
>      \RemoveAllEmptyStaves
>      \override VerticalAxisGroup.remove-layer = 1
>      instrumentName = "Flute 1"
>      shortInstrumentName = "Fl. 1"
>    } <<\global \flOne>>
>    \new Staff \with {
>      \RemoveAllEmptyStaves
>      \override VerticalAxisGroup.remove-layer = 1
>      instrumentName = "Flute 2"
>      shortInstrumentName = "Fl. 2"
>    } <<\global \flTwo>>
>    \new Staff \with {
>      instrumentName = "Flutes"
>      shortInstrumentName = "Fl. 1-2"
>      \override VerticalAxisGroup.remove-layer = 2
>    } \partCombine \flOne \flTwo
I've been trying for a while to extend this approach to handle a typical 
Concerto Grosso score with multiple solo parts, where I want to keep the 
solo parts in a separate GrandStaff and the tutti parts in another 
GrandStaff below. The following example is very close to what I would 
like, and doesn't even need the Keep_alive_together_engraver, it's 
enough to play around with the keepAliveInterfaces:

\version "2.24.0"

\layout{
  short-indent = 2\cm
  indent = 3\cm
  \context{
    \Staff
    \RemoveAllEmptyStaves
  }
}

viI = \fixed c'{
  \repeat unfold 10 {c2 e | }
  \tag #'viIsolo {
       \unset Staff.keepAliveInterfaces
       \repeat unfold 10 {c'4 d' e' f' }
       \set Staff.keepAliveInterfaces = #'()
     }
  \tag #'viItutti {\repeat unfold 10 {e1 }}
  \repeat unfold 10 {c2 e | }
}

viII = \fixed c'{
  \repeat unfold 10 {c2 c | }
  \tag #'viIIsolo {
    \unset Staff.keepAliveInterfaces
    \repeat unfold 5 {e4 g e c }
        \set Staff.keepAliveInterfaces = #'()
       }
  \tag #'viIItutti {\repeat unfold 5 {c1 }}
  \repeat unfold 15 {c2 c | }
}

\score{
  <<
    \new GrandStaff <<
      \new Staff \with {instrumentName = "Violin I Solo" 
shortInstrumentName = "Vi I Solo" }
        { \set Staff.keepAliveInterfaces = #'() \keepWithTag #'viIsolo 
\viI }
      \new Staff \with {instrumentName = "Violin II Solo" 
shortInstrumentName = "Vi II Solo" }
        { \set Staff.keepAliveInterfaces = #'() \keepWithTag #'viIIsolo 
\viII }
    >>
    \new GrandStaff <<
      \new Staff \with {instrumentName = "Violin I" shortInstrumentName 
= "Vi I "}
        \keepWithTag #'viItutti \viI
      \new Staff \with {instrumentName = "Violin II" 
shortInstrumentName = "Vi II" }
        \keepWithTag #'viIItutti \viII
    >>
  >>
  \layout{}
}

I can even automate it a bit, using pushToTag and appendToTag:

\version "2.24.0"

\layout{
  short-indent = 2\cm
  indent = 3\cm
  \context{
    \Staff
    \RemoveAllEmptyStaves
  }
}

viI = \fixed c'{
  \repeat unfold 10 {c2 e | }
  \tag #'viIsolo { \repeat unfold 10 {c'4 d' e' f' } }
  \tag #'viItutti {\repeat unfold 10 {e1 }}
  \repeat unfold 10 {c2 e | }
}

viII = \fixed c'{
  \repeat unfold 10 {c2 c | }
  \tag #'viIIsolo { \repeat unfold 5 {e4 g e c } }
  \tag #'viIItutti {\repeat unfold 5 {c1 }}
  \repeat unfold 15 {c2 c | }
}

\score{
  <<
    \new GrandStaff <<
      \new Staff \with {instrumentName = "Violin I Solo" 
shortInstrumentName = "Vi I Solo" }
        { \set Staff.keepAliveInterfaces = #'()
      \pushToTag #'viIsolo { \unset Staff.keepAliveInterfaces }
      \appendToTag #'viIsolo { \set Staff.keepAliveInterfaces = #'()}
      \keepWithTag #'viIsolo \viI }
      \new Staff \with {instrumentName = "Violin II Solo" 
shortInstrumentName = "Vi II Solo" }
        { \set Staff.keepAliveInterfaces = #'()
      \pushToTag #'viIIsolo { \unset Staff.keepAliveInterfaces }
      \appendToTag #'viIIsolo { \set Staff.keepAliveInterfaces = #'()}
      \keepWithTag #'viIIsolo \viII }
    >>
    \new GrandStaff <<
      \new Staff \with {instrumentName = "Violin I" shortInstrumentName 
= "Vi I "}
        \keepWithTag #'viItutti \viI
      \new Staff \with {instrumentName = "Violin II" 
shortInstrumentName = "Vi II" }
        \keepWithTag #'viIItutti \viII
    >>
  >>
  \layout{}
}

The only remaining problem is if I want to to have different 
shortInstrumentNames in the lower GrandStaff; "Vi tutti" if the solo 
part is playing in parallel and "Vi unis." if the solo and tutti play in 
unison. As long as there's a single solo part, I can obtain it using the 
trick described in David's example above with 
Keep_alive_together_engraver (at the Score level) and different 
remove-layer values, but that doesn't extend to the case of multiple 
solo instruments, since the action of the Keep_alive_together_engraver 
should be done separately for the group of "Vi I Solo", "Vi I tutti" and 
"Vi I unis", and for the group of "Vi II Solo", "Vi II tutti" and "Vi II 
unis". Since this logical grouping of staves is orthogonal to the way 
they are split in GrandStaffs in the score, I cannot see any way to 
implement that.

An almost working alternative, would be to change the value of 
shortInstrumentName on the fly, but if a solo part only spans part of a 
staff line, the shortInstrumentName will change back again before the 
correct version is typeset, so it will only work if line breaks happen 
to end up at the right place.

Any clever ideas, or have I hit a hard limitation?

    /Mats