It is neede to implement a function to configure compilation for musixflx Latex files. The reason is that Musixtex Latex package has been used in Music projects.
An stand alone example is as follow:
\documentclass[%
border={2pt -8pt 2pt -10pt},% left bottom right top
%border=8pt
varwidth]{standalone}
\usepackage{tikz}
\usetikzlibrary{positioning}
\usepackage{musicography}
\usepackage{musixtex}
\input musixlyr
\usepackage{amsmath}
\usepackage{xcolor}
\xdefinecolor{red-undar}{RGB}{179,35,79}
\usepackage{fontawesome5}
\begin{document}
\begin{music}
\hsize=\linewidth%
\resetlyrics
\setlyrics{Acordes}{\B I7 \B II7 \B III7 \B IV7 \B V7 \B VI7 \B VII7 \B I7 \B I7 \B II7 \B III7 \B IV7 \B V7 \B VI7 \B VII7 \B I7}%
\setsongraise{1}{-0.3cm}
\font\A=phvb8t at 10pt% added for letter type.
\font\B=phvb8t at 13pt% added for letter type.
\parindent0mm
\sepbarrules
%\generalsignature{-3}
%\generalmeter{\meterfrac{2}2}
\instrumentnumber{1}
%\setinterinstrument{1}{12pt}%espacio entre Voz y Piano
%\interstaff{12}%espacio entre pentagramas del piano
%
\stafftopmarg5\Interligne%
%\staffbotmarg6\Interligne% set verticle space in one staff score
\setclef1\treble%
%\setstaffs12
\nobarnumbers
%\smallmusicsize
\startpiece
\A\assignlyricsmulti{1}{1}{Acordes}
\NOtes\qsk\zwh{c}\zwh{e}\zwh{g}\wh{i}\zcharnote{8}{\hspace{-2.7cm}%
\begin{tikzpicture}%
%\useasboundingbox (0.2,0) rectangle (-4.1,5.4);
\node (point) at (0,0){};
\node[text width=4.5cm,text centered,] {\textcolor{red-undar}{\A\textbf\centering{Modo mayor}}};
%\draw[red] (current bounding box.south west) rectangle (current bounding box.north east);
\end{tikzpicture}}%
\en%
\NOtes\zwh{d}\zwh{f}\zwh{h}\wh{j}\en%
\NOtes\zwh{e}\zwh{g}\zwh{i}\wh{k}\en%
\NOtes\zwh{f}\zwh{h}\zwh{j}\wh{l}\en%
\NOtes\zwh{g}\zwh{i}\zwh{k}\wh{m}\en%
\NOtes\zwh{h}\zwh{j}\zwh{l}\wh{n}\en%
\NOtes\zwh{i}\zwh{k}\zwh{m}\wh{o}\en%
\NOtes\zwh{j}\zwh{l}\zwh{n}\wh{p}\en\setdoubleBAR\alaligne%
%\setclef1\bass\changeclefs\alaligne%
\NOtes\zwh{a}\zwh{c}\zwh{e}\wh{g}\zcharnote{8}{\hspace{-2.7cm}%
\begin{tikzpicture}%
%\useasboundingbox (0.2,0) rectangle (-4.1,5.4);
\node (point) at (0,0){};
\node[text width=4.5cm,text centered,] {\textcolor{red-undar}{\A\textbf\centering{Modo menor}}};
%\draw[red] (current bounding box.south west) rectangle (current bounding box.north east);
\end{tikzpicture}}%
\en%
\NOtes\zwh{b}\zwh{d}\zwh{f}\wh{h}\en%
\NOtes\zwh{c}\zwh{e}\zwh{g}\wh{i}\en%
\NOtes\zwh{d}\zwh{f}\zwh{h}\wh{j}\en%
\NOtes\zwh{e}\zwh{^g}\zwh{i}\wh{k}\en%
\NOtes\zwh{f}\zwh{h}\zwh{j}\wh{l}\en%
\NOtes\zwh{^g}\zwh{i}\zwh{k}\wh{m}\en%
\NOtes\zwh{h}\zwh{j}\zwh{l}\wh{n}\en\setdoubleBAR%
\nolyr%
\lyricsoff%
\endpiece
\end{music}
\end{document}
It will be very usefull to implement the musixflx compilation functionality in RStudio.
Regards