int speakerPin = 16;

void setup() {
  // initialize serial communications (for debugging only):
  Serial.begin(9600);
  randomSeed(analogRead(A0));
}

void loop() {
  // make random not in the output pitch range (120 - 1500Hz)
 int thisPitch = random(120, 800);
 Serial.println(thisPitch);
  // play the pitch:
  tone(speakerPin, thisPitch, 500);
  delay(100);   
}