Fitting more systems on the first page of a Lilypond score

Question

I'm working to improve upon an excellent sheet I found of Debussy's Deuxième Arabesque on the freely available Mutopia Project.

In particular, I'm interested in fitting the music on fewer pages but I struggle to have the first page display five systems instead of four with the version I arrived at.

From the reproduction above, I would like the fith system (starting at bar 13) to be at the bottom of the first page. It seems there are a lot of wasted space on the first page and I'm rather confident it will fit perfectly.

I have a hard time playing figuring out how to achieve this. I have displayed the spacing annotations as advised by the documentation but I do not seem to be able to make sense of it.

Answer 1

If I were typesetting this today, I would try changing the staff size, like this:

#(set-global-staff-size 18)

Answer 2

You can add the following to your paper block

\paper {
  min-systems-per-page = #5
  system-system-spacing.padding = #2  %fit staves closer together
  system-system-spacing.stretchability = #15  %how flexible the spacing is
}

This will of course force that all other pages have at least five systems. You can play around with the padding and stretchability values and see what works best. Also, you might want to make the staves smaller than the default 20pt. To do that, you can add the following at the beginning of the file:

#(set-global-staff-size 18)