int loadBank(int bank) {

  memset(_sample, 0, sizeof(Mix_Chunk*) * NUM_WAVEFORMS);

  int result = Mix_OpenAudio(44100, AUDIO_S16SYS, 2, 512);
  if( result < 0 ) {
    fprintf(stderr, "Unable to open audio: %s\n", SDL_GetError());
    exit(-1);
  }

  result = Mix_AllocateChannels(4);
  if( result < 0 ) {
    fprintf(stderr, "Unable to allocate mixing channels: %s\n", SDL_GetError());
    exit(-1);
  }

  char waveFileName[17];

  for( int i = 0; i < NUM_WAVEFORMS; i++ ) {
    sprintf(waveFileName, "banks/BANK%d/%d.wav", bank, i+1);

    _sample[i] = Mix_LoadWAV(waveFileName);
    if( _sample[i] == NULL ) {
      fprintf(stderr, "Unable to load wave file: %s\n", waveFileName);
    }
  }

  return true;
}