Spinet

int trig = 2;

int echo = 3;
int pin = 9;
void setup()
{
  Serial.begin(9600);
  pinMode(trig, OUTPUT);
  pinMode(echo, INPUT);
  pinMode(pin, OUTPUT);
}
void loop()
{
  int duration , distance;
  digitalWrite(trig, HIGH);
  delayMicroseconds(10);
  digitalWrite(trig, LOW);
  duration = pulseIn(echo, HIGH);
  distance = (duration / 2) / 21.9;
  Serial.print(distance);
  Serial.print("cm");
  delay(50);

  if (distance < 3)

  {

    tone(pin, 1318.5);
  }
  else if ((3 < distance) && (distance < 6))
  {
    tone(pin, 1244.5);

  }
  else if ((6< distance) && (distance < 9))
  {
    tone(pin, 1174.7);
  }
  else if ((9 < distance) && (distance < 12))
  {
    tone(pin, 1108.7);
  }
  else if ((12 < distance) && (distance < 15))
  {
    tone(pin, 1046.5);
  }
  else if ((15 < distance) && (distance < 18))
  {
    tone(pin, 987.77);
  }
  else if ((18 < distance) && (distance < 21))
  {
    tone(pin, 932.33);
  }
  else if ((21 < distance) && (distance < 24))
  {
    tone(pin, 880);
  }
  else if ((24 < distance) && (distance < 27))
  {
    tone(pin, 830.61);
  }
  else if ((27 < distance) && (distance < 30))
  {
    tone(pin, 783.99);
  }
  else if ((30 < distance) && (distance < 33))
  {
    tone(pin, 739.99);

  }
  else if ((33 < distance) && (distance < 36))
  {
    tone(pin, 698.46);
  }
 

  
  else
  {
    noTone(pin);
  }
}