int buzzerPin = 9;
float sinVal; // sine value
int toneVal; // sound frequency

void setup() {
  // put your setup code here, to run once:
  pinMode(buzzerPin, OUTPUT);

}

void loop() {
  // put your main code here, to run repeatedly:
  for(int x = 0; x < 360; x++){
    sinVal = sin(x*(PI/180)); // get sine of x
    toneVal = 2000 + sinVal * 500; // sound frequency according to sine value
    tone(buzzerPin, toneVal); // output sound frequency
    delay(1);
  }
}