Bassclef is too low

\documentclass[varwidth=true, border=2pt]{standalone}
\usepackage[ngerman]{babel}
\usepackage[utf8]{inputenc}
% Color
\usepackage{color}
\definecolor{lightgray}{gray}{0.95}

%Additional package
\usepackage{musixtex}

%document
\begin{document}{\textcolor{lightgray}{a}}\begin{music}\bassclef\end{music}{\textcolor{lightgray}{b}}
\end{document}