const int SoundPin = 9;
int DelaySound = 500;
void setup() {
}

void loop() {
if(digitalRead(2) == LOW){
  digitalWrite(7, HIGH);
  delay(500)
  digitalWrite(7, LOW);
  delay(250)
}
if(digitalRead(2) == HIGH){
  tone(SoundPin, 262); // ДО
  delay(DelaySound);
  noTone(9);
  delay(DelaySound);
  tone(SoundPin, 294); //РЕ
  delay(DelaySound);
  noTone(9);
  delay(DelaySound);
  tone(SoundPin, 329);//МИ
  delay(DelaySound);
  noTone(9);
  delay(DelaySound);
  tone(SoundPin, 349);//ФА
  delay(DelaySound);
  noTone(9);
  delay(DelaySound);
  tone(SoundPin, 392);//СОЛЬ
  delay(DelaySound);
  noTone(9);
  delay(DelaySound);
  tone(SoundPin, 440);//ЛЯ
  delay(DelaySound);
  noTone(9);
  delay(DelaySound);
  tone(SoundPin, 494);//СИ
  delay(DelaySound);
  noTone(9);
  delay(DelaySound);
}