#define BUZZER_PIN 4
#define BUTTON_PIN 2
#define NOTE_C5  523

void setup() {
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  pinMode(BUZZER_PIN, OUTPUT);

}

void loop() {

  if (!digitalRead(BUTTON_PIN)) {
    tone(BUTTON_PIN, NOTE_C5);
  } else {
    noTone(BUTTON_PIN);
  }

  delay(10); // this speeds up the simulation
}