Re-sizing score on the fly

[Don Gingrich]

This is an unusual problem. I've got a bunch of
scores that I process to PDF and include in a a
LaTeX "container" document to produce a booklet
of nearly 200 pages at this point. But I also want
to be able to print them as individual scores.

When I'm "including" a score, I push the margins
to nearly the edge so that when they are "included"
they are the proper size on the page and allow for
page numbers (and I could probably put a header
in the top margin or footnote identifying the book
in the bottom margin.

What I'm also doing is using two different files
to set margins on the page, etc.

For include I use:
\version "2.18.2"
\paper {
  paper-width = 21.0\cm
  paper-height = 29.7\cm
  top-margin = 1.0\cm
  bottom-margin = 2.0\cm
  left-margin = 0.5\cm
  right-margin = 0.5\cm
  indent = 0
  %%set to ##t if your score is less than one page:
  ragged-last-bottom = ##t
}

For separate I use:
\version "2.18.2"
\paper {
paper-width = 21.0\cm
  paper-height = 29.7\cm
  line-width    = 190\mm
  left-margin   = 1.0\cm
  top-margin = 1.0\cm
  bottom-margin = 2.0\cm
  indent = 0
  %%set to ##t if your score is less than one page:
  ragged-last-bottom = ##t
  ragged-bottom = ##f
}

And I've been using:
\include "/home/don/Documents/music/busking/stand-alone.ly"
or
\include "/home/don/Documents/music/busking/booklet.ly"

My template for a lead sheet has both and I "comment-out"
the one that doesn't apply.

The problem comes in with the
#(set-global-staff-size 21.8)
directive.

Because I'm ageing (aren't we all), I try to make the
staves and lyrics as large as possible. But, as large
as possible for an included file over two pages can
mean three pages when it's stand-alone, or smaller than
it could have been if it was set for stand-alone and is
then printed with the smaller margins for inclusion.

Is there a way to use a "multiplier" that I could set in
the above two files and multiply in the
set-global-staff-size to make this "automagic"?

variable=xxx

multiplier=y.yy

#(set-global-staff-size variable*multiplier)

Then the multiplier would reside in the included files, the
variable would be in the score file, and by including
the correct file I could have either type of score.
I'm fairly certain that if I could use a relative path
in the include and a series of hard links between a pair
of directories on my Linux system, I should be able to
maintain two sets of scores from a single "master" set.
This would make me very happy. :-)

If you've got this far, thank you for your patience.

Cheers,

-Don