Re: different tempi

[Werner LEMBERG]

> I would need something like this:
> 
>     StaffGroup  /
>       Staff     |      |      |
>       Staff     |      |      |
>       Staff     |   |    |     |
>       Staff     |      |      |
>                 \
> 
> I can imagine two solutions:
> 
>   (a) If you move the bar line engraver to Staff context, StaffGroup
>       honours a new Staff property, say, `suppressBarline', to do
>       the obvious.
> 
>   (b) Provide, as a property of StaffGroup, a staff list which gets
>       bar lines (enumerated, say, from bottom to top).  For the
>       example above, it would be (1 3 4).

After some thinking, I believe this is the wrong approach.  Reason:
Sometimes it is necessary to do things like this:

                 /
                 |      |      |
                 |      |      |
                 |   |    |     |
                 |   |    |     |
                 \
                 /
                 |      |      |
                 |      |      |
                 |   |    |     |
                 |   |    |     |
                 \

Such `nested' StaffGroups aren't possible.  Instead, I propose an
`OuterStaffGroup' which embraces all staves in a system, providing
manipulation of the accolade setup and nothing else: The example above
would then look like this:

  OuterStaffGroup
    systemStartDelimiterHierarchy = #'((SystemStartBracket 1 2 3 4)
                                       (SystemStartBracket 5 6 7 8))
    StaffGroup
      Staff
      Staff
    StaffGroup
      Staff
      Staff

    StaffGroup
      Staff
      Staff
    StaffGroup
      Staff
      Staff


         Werner