Used internally to get a group of choosable tracks.

def _get_selectable(self):
        '''
        Used internally to get a group of choosable tracks.
        '''
        # Save some typing
        cursong = self.loop[self.song][0]
        
        if self.dif_song and len(cursong) > 1:
            # Position is relative to the intro of the track,
            # so we we will get the both the intro and body.
            s = cursong[0] + cursong[1]
        else:
            # Position is relative to the body of the track, so just get that.
            s = cursong[-1]
        # Return what we found
        return s