public void decreaseBPM() {
   int bpm = model.getBPM();
   model.setBPM(bpm - 1);
 }
 public void setBPM(int bpm) {
   model.setBPM(bpm);
 }
 public void increaseBPM() {
   int bpm = model.getBPM();
   model.setBPM(bpm + 1);
 }