char LVL1;
char LVL2;
char LVL3;
char LVL4;
 
 const int L1Freq = 3312;
 const int L2Freq = 3354;
 const int L3Freq = 3419;
 const int L4Freq = 3463;

 const char FreqPIN = 11;
 int i = 0;

void setup() {

Serial.begin(9600);

pinMode(2, INPUT);
pinMode(3, INPUT);
pinMode(4, INPUT);
pinMode(5, INPUT);

}

void loop() {

  LVL1 = digitalRead(5);
  LVL2 = digitalRead(4);
  LVL3 = digitalRead(3);
  LVL4 = digitalRead(2);

  if(!LVL1 && !LVL2 && !LVL3 && !LVL4){
    noTone(FreqPIN);
  } else if(LVL4){
    tone(FreqPIN, L4Freq);
    Serial.println(L4Freq);
  } else if(LVL3) {
    tone(FreqPIN, L3Freq);
    Serial.println(L3Freq);
  } else if(LVL2) {
    tone(FreqPIN, L2Freq);
    Serial.println(L2Freq);
  } else if(LVL1) {
    tone(FreqPIN, L1Freq);
    Serial.println(L1Freq);
  } else {
    noTone(FreqPIN);
    Serial.println(0);
  }
  i++;
  Serial.println(String(i));
  delay(500);
}