Re: StaffGroup bar line problem in polymetric notation

[Carl Sorensen]

Libero Mureddu <libero.mureddu <at> gmail.com> writes:

> 
> Hi all,
> I'm working, once again, on a polymetric score and I have the 
> following problem:
> starting from the example from the 1.2.3.4 section of the doc, "Staves
> with different time signatures, unequal bar lengths",
> I tried to group all the staves in a StaffGroup, and, reasonably, Lily
> added a Group barline.
> 
> Then, I added a StaffGroup context in which I removed the 
> "Span_bar_engraver".
> Until here everything is fine 
> However, as one can see in the attached file, all voices meet each
> other at a certain point, and before that note I'd like to have (for
> sake of clarity) a Group bar crossing all staves.
> 

If you remove the StaffBar engraver, then you can never get Staff Bars 
engraved.

So instead, you want to \override the StaffBar #'stencil to ##f:

\override StaffGroup.StaffBar #'stencil = ##f.

This prevents printing of staff bars.

When you want to print staff bars, just revert the override:

\revert StaffGroup.StaffBar #'stencil

I've tested your code, and it works, except for the fact that the last
staff is not at the same time as the rest.

Here it is for you:

%% Start of code

\version "2.11.48"

\layout {
       \context {
         \Score
         \remove "Timing_translator"
         \remove "Default_bar_line_engraver"
       }
       \context {
               \StaffGroup
               % \remove "Span_bar_engraver"
       }
               \context {
         \Staff
         \consists "Timing_translator"
         \consists "Default_bar_line_engraver"
       }
     }

     % Now each staff has its own time signature.

     \relative c' <<
     \new StaffGroup <<
      \override StaffGroup.SpanBar #'stencil = ##f
      { \time 3/4
         c4 c c |
         c c c |
         c8
       }
       \new Staff {
         \time 2/4
         c4 c |
         c c |
         c c |
         \revert  StaffGroup.SpanBar #'stencil
         c8
         %\override StaffGroup.SpanBar #'stencil = ##f
       }
       \new Staff {
         \time 3/8
         c4. |
         c8 c c |
         c4. |
         c8 c c |
         c8
       }
       \new PianoStaff <<
            \new Staff { \time 6/8
            c2. |
            c |
            c8}
            \new Staff { \time 6/8
            c2. |
            c2. |
            c8}
          >>

       >>
     >>

%% End of code


Hope this helps, 


Carl