int buzzer=21;
int led1=17;

void setup() {
  pinMode(buzzer, OUTPUT);

  pinMode(led1, OUTPUT);
}

void loop() {
  tone(buzzer,800);
  digitalWrite(led1, HIGH);
  delay(1000);
  noTone(buzzer);
  digitalWrite(led1, LOW);
  delay(2000);
  tone(buzzer,400);
  digitalWrite(led1, HIGH);
  delay(2000);
  noTone(buzzer);
  digitalWrite(led1, LOW);
  delay(2000);
  tone(buzzer,200);
  digitalWrite(led1, HIGH);
  delay(1000);
  noTone(buzzer);
  digitalWrite(led1, LOW);
  delay(2000);
}