%% nota - tón
\newcommand\note[1]{\xnote#1\relax\relax\relax}
        \def\xnote#1#2#3\relax{#1\if#2\relax\else\if b#2$\flat\if#3\relax%
        \else_{#3}\fi$\else\if###2$\sharp\if#3\relax\else_{#3}\fi$\else$_{#2}$\fi\fi\fi}
  
%% záporná nota
\def\noteminus{%
  \setbox0=\hbox{-}%
  \vcenter{%
    \hrule width\wd0 height \the\fontdimen8\textfont3%
  }%
}

