% !TEX TS-program = lualatex
% !TEX encoding = UTF-8
\documentclass[11pt]{article}
\usepackage{fontspec}
\usepackage{gregoriotex}
\begin{document}
\begin{center}\begin{huge}\textsc{Populus Sion}\end{huge}\end{center}
\redlines
\gresetfirstlineaboveinitial{\small \textsc{\textbf{VII}}}{\small \textsc{\textbf{VII}}}
\commentary{{\small \emph{Cf. Is. 30, 19 . 30 ; Ps. 79}}}

% and finally we include the score. The file must be in the same directory as this one.
\includescore{populussion}

\end{document}
