VBlank Interrupt:

  This gadget is used to help people who's  still  using  SoundTracker  and
  NoiseTracker  modules,  containing  VBlank speed commands bigger than 1F.
  These can under normal conditions sound to slow, played by  this  player.
  But  checking  this  gadget, will cause the player to interpret all speed
  commands in the module as VBlank speed commands, which will  correct  the
  speed errors.

  Default is OFF.