\documentclass{article}
\usepackage{musixtex}
\usepackage{musixtab}

\begin{document}

\begin{music}
\instrumentnumber{1}
\setstaffs1{1}
\TAB1              % enable tablature
\setname1{Guitar}
\generalmeter{\meterfrac44}

\startextract

% strings numbered 1 (high E) to 6 (low E)
% \ztab{string}{fret}

\Notes
  \ztab{6}{3}   % G on low E string
  \ztab{5}{2}   % B on A string
  \ztab{4}{0}   % D open
  \ztab{3}{0}   % G open
\en \bar

\Notes
  \ztab{2}{1}
  \ztab{1}{0}
  \ztab{2}{1}
  \ztab{3}{0}
\en \doublebar

\endextract
\end{music}

\end{document}