French scores: instrument names and time signatures

[Michael J. O'Donnell]

I am using "French" scores, with silent staves removed, even on the
first line (these pieces would have way too much stuff on the first line
otherwise). I would like for the first entry of a given staff (and, in
some cases, re-entry after a long silence) to carry time signature and
instrument names.

I can almost kludge this up, once I know approximately where the line
breaks go. I can define "shortInstrumentName" just before the appearance
of a staff, and blank it out in the second line (notice that this
requires approximate knowledge of two line breaks). But, I don't see how
to provide extra indentation so that the instrument names will fit in
the margin. All of the methods I see for defining margins and
indentation appear to be global.

Then, I can add a redundant time signature declaration at the appearance
of a staff, plus I have to fiddle the time signature visibility just
before, to suppress a pointless repetition of time signature on the
staves that are already there (particularly when they are about to
disappear):

     \once \override Score.TimeSignature #'break-visibility = #'#(#f #t #t)

>From trial and (lots of) error, it appears crucial to define this
visibility at the Score level, else the time signature becomes
transparent, but still takes up space, which looks even sillier than the
repeated time signature. This works in my example, but worries me for
the future since there might be unfortunate interactions with other staves.

I am tempted in some cases to start some of the staves at their first
appearances, rather than letting the silent parts be removed. But this
requires precise knowledge of at least one line break. It also makes the
relationship between layouts of combined scores and single parts more
complicated, since in one case rests are omitted (not removed, but
omitted from the voice definition) at the beginning, and in the other
case they must be there.

It appears to me that a proper robust solution will require some hacking
of the engravers, which I won't attempt yet. But, I'm fishing for tips
from someone with another idea ...

Cheers,

Mike O'Donnell