How to force a page break in LilyPond

Question

I'm trying to force a page break by using the manual page breaking mode in LilyPond. Yet, I cannot make a working example. Consider this snippet (main.ly)

\version "2.22.2"
\include "lilypond-book-preamble.ly"

RightHand = { 
    <e g c>4 <e g c> <b d g> <b d g> |
    <a c e> <a c e>8 <a c e> <a c e>4 <a c d> |
    <e' g c>4 <e g c> <b d g> <b d g> |
    <f' a>4 <e g>8 <d f> <c e g>4 <c e g> \bar "|."
}
LeftHand = {
    c8 c'4 c16 f,16 g8 g,4 g'8 |
    a,8 a'4 <g, g'>8 <f f'>8 f'4 f8 |
    c8 c'4 c16 f,16 g8 g,4 g8 |
    f8 f'4. c8 c'4 c8 \bar "|."
}

\paper {
    page-breaking = #ly:page-turn-breaking
}

\score {
    \new PianoStaff
    <<
        \new Staff {
            \relative c' {
                \clef G
                \RightHand
                \pageBreak
                \RightHand
            }
        }
        \new Staff {
            \relative c, {
                \clef F
                \LeftHand
                \pageBreak
                \LeftHand
            }
        }
    >>
}

How would I force a page break between the two lines? I tried replacing the \pageBreak command with \pageTurn, and also tried different ways to structure the score. None of them work, by which I mean that the resulting pdf is a one-page document with all the music on the same page.

I compile this example with

lilypond-book --pdf main.lytex

where the content of main.lytex is

\documentclass[letterpaper,12pt]{article}
\begin{document}                                                                                             
\lilypondfile{main.ly}
\end{document}

and the resulting main.tex is compiled with LaTeX.

Answer 1

lilypond-book is not really intended for what you appear to be trying to do. lilypond-book intended for embedding short pieces of music into a LaTeX-document. This means that lilypond-book hands all of the page spacing decisions to LaTeX. This is done by splitting the score into individual systems and passing these to LaTeX, which allows LaTeX to make it’s own decisions about spacing and page breaking.

This means that you need to do page breaks from withing LaTeX, not Lilypond. While you can use \betweenLilyPondSystem to have lilypond-book somehow manage this the easiest way would be to use multiple LilyPond-Sections with page breaks in between.

If you want to include a longer example of music with multiple pages it would be adviseable to create the score in Lilypond and embed this into the LaTeX file.

Answer 2

You try a forced marriage between lilypond and LaTeX. But it is already a difficult relationship. I don't know, if you saw it, but lilypond-book creates pdf-snippets, which are inserted after. I switched to creating them manually very early. For this purpose I wrote a LaTeX package. I will publish it hopefully in the next weeks. You can find it here: https://github.com/MaestroGlanz/Lieder-Package

You should have a look into that. Maybe it solves your problem.