Lilypond-book and TeXshop on Mac: Newbie questions

[Dona Mommsen]

Hi,

I'm an occasional user of Lilypond and so far, I've created only smaller 
examples. I'm neither an experienced user with Latex, so bare with me.

I'm trying to use Lilypond-book (v.2.14.2) with TeXShop (v2.43) on Mac OS X 
(v10.7.3).
The installation worked and I can run a small test-file:
1. I create a myfile.lytex in TexShop
2. I can run lilypond-book from the command line
3. I open the ./out/myfile.tex in TexShop and do the typesetting as I usually 
would for a Latex file.

Sofar, myfile.lytex only calls lilypond-files with snippets.

Here are my first questions (sure more to follow…):
A. – I'm trying to simplify the usage. Ideally, I'd like to do the three steps 
mentioned above in one call to the "typeset"-command in TeXShop. Is there a way 
to do this?
– One reason I'd like to do this: When I change only some text in .lytex and 
run lilypond-book, the file ./out/myfile.tex does not get updated because all 
the lilypond-snippets are up to date. Any remedy to that in the command-line 
usage of lilypond-book?

B. Layout question:
One of the files that I include has no page-size indications. It's basically a 
big StaffGroup and the width fits on a A4 page with no problem.
When I include the same file within a .lytex file, it does not fit anymore; the 
StaffGroup gets cut in the middle and is spread on 2 pages width.

Thanks in advance for any help,

Dona