Quoting Peder Hedlund <peder(a)musikhuset.org>rg>:
It'll display the currently loaded
"patches" which you can use by
changing the sound on your MIDI keyboard to that value.
Correction: if you start it with '-p popular.pgm' you can change
"patches".
By default you're loading the default.pgm which enables you to modify
the preset sound (adding overdrive, changing reverb et.al.) by
selecting the correspondent sound - 1 on your keyboard (the 1:st
sound/patch corresponds to patch 0 on the keyboard, at least on my
Korg WS).