> The (pdf|Xe|(dvi)?Lua)?(La)?TeX experts in the room are going to
> find this question ridiculous, but anyway: how do I use the code
> here?
>
> https://lilypond.org/doc/v2.23/Documentation/usage/sharing-the-table-of-contents.html
Here is an enhanced replacement. For simplicity I didn't convert the
code into a style file.
```
\usepackage{xifthen}
\usepackage{catchfile}
\usepackage{pdfpages}
% Include a LilyPond score with an optional table of contents.
% This macro is a wrapper for the `\includepdf` command from the
% 'pdfpages' LaTeX package.
%
% Syntax:
%
% \includescore{scorefile}
% \include[tocfile]{scorefile}
%
% `scorefile` is the name of a PDF file. `tocfile` is the name
% of a file containing entries for the master file's table of
% contents; see option 'addtotoc' in the 'pdfpages'
% documentation for the exact syntax.
\newcommand{\includescore}[2][]{%
\ifthenelse{\isempty{#1}}%
{\includepdf[pages=-]{#2}}%
{\CatchFileDef{\IStoclines}{#1}{}%
\edef\includeit{%
\noexpand\includepdf[pages=-,addtotoc={\IStoclines}]{#2}}%
\includeit}%
}
```
Assuming the above is in a file called `includescore.tex` and the TOC
lines in file `bar.toclines`, an example call could be
```
\documentclass{article}
\include{includescore}
\begin{document}
\tableofcontents
\section{foo}
This is a test chapter, followed by a score without an associated
tocfile.
\includescore{foo.pdf}
\section{bar}
This is a test chapter, followed by a score with an associated
tocfile.
\includescore[bar.toclines]{bar.pdf}
\section{baz}
End of tests.
\end{document}
```
