void drawBeat(String inputString) {
  int height = charToInt(inputString[0]);
  int color = random(red, white);
  for (int xpos = 0; xpos < cubeSides; xpos++) {
    for (int ypos = 0; ypos < cubeSides; ypos++) {
      for (int zpos = 0; zpos < height; zpos++) {
          drawLed(color, xpos, ypos, zpos);
      }
    }
  }
}