MusiXTeX is a set of TeX macros to typeset polyphonic, orchestral or
polyphonic music. 

If you are not familiar with TeX at all I would recommend to find another 
software package to do musical typesetting. Setting up TeX and MusiXTeX
on your machine and mastering it is an awesome job which gobbles up
a lot of your time and disk space. But, once you master it...

MusiXTeX is documented in /usr/local/lib/texmf/documentation/musixtex.tex. This
file must be processed  with LaTeX and musixflx:
  latex  musixdoc
  musixflx musixdoc
  latex  musixdoc
  makeindex musixdoc.idx
  latex  musixdoc
  makeindex musixdoc.idx
  latex  musixdoc

A few examples are provided in the directory
    /usr/local/lib/texmf/documentation/musixtex.examples
for instance, to typeset the file 'traeumer.tex' type:
  musixtex traeumer
  musixflx traeumer
  musixtex traeumer