Tunes:

  A module normally consists of 1 tune only, but players like SID and  TFMX
  supports  more  tunes in one module. You can choose between the different
  tunes using  the keys 1-9 and 0 for  10. Of course,  you can also use the
  numeric keyboard. If there  are more than  10 tunes, you  may use "+" and
  "-" to skip to the  next 10 tunes or to go back to the previous 10 tunes.
  The only place where you can't do it is in the sample info window.
  The "(x/y)" in the title bar shows "current tune/total number of tunes".
  If you zip the window, this will instead show the position/length.