\documentclass[a4paper, 12pt]{article}

\usepackage{graphics}
\begin{document}

\section{Using lilypond-book's fragment option}

If a snippet is not a fully valid LilyPond file, you have
to use the \verb|fragment| option:

{%
\parindent 0pt
\noindent
\ifx\preLilyPondExample \undefined
\else
  \expandafter\preLilyPondExample
\fi
\def\lilypondbook{}%
\input{81/lily-ad4d23c7-systems.tex}
\ifx\postLilyPondExample \undefined
\else
  \expandafter\postLilyPondExample
\fi
}

% TODO: \verb does not yet work!!!
There is also a shorthand version %\verb|\lilypond[fragment]{c' e' g'}|:

{%
\parindent 0pt
\noindent
\ifx\preLilyPondExample \undefined
\else
  \expandafter\preLilyPondExample
\fi
\def\lilypondbook{}%
\input{24/lily-400d0b93-systems.tex}
\ifx\postLilyPondExample \undefined
\else
  \expandafter\postLilyPondExample
\fi
}

\end{document}