This is the program for arduino of the song "Fur Elise". You can play it with an arduino, a buzzer and, if you want, a led. Enjoy the program! :)

Fur Elise - Arduino Buzzer

// Musical Notes
#define NOTE_B0  31
#define NOTE_C1  33
#define NOTE_CS1 35
#define NOTE_D1  37
#define NOTE_DS1 39
#define NOTE_E1  41
#define NOTE_F1  44
#define NOTE_FS1 46
#define NOTE_G1  49
#define NOTE_GS1 52
#define NOTE_A1  55
#define NOTE_AS1 58
#define NOTE_B1  62
#define NOTE_C2  65
#define NOTE_CS2 69
#define NOTE_D2  73
#define NOTE_DS2 78
#define NOTE_E2  82
#define NOTE_F2  87
#define NOTE_FS2 93
#define NOTE_G2  98
#define NOTE_GS2 104
#define NOTE_A2  110
#define NOTE_AS2 117
#define NOTE_B2  123
#define NOTE_C3  131
#define NOTE_CS3 139
#define NOTE_D3  147
#define NOTE_DS3 156
#define NOTE_E3  165
#define NOTE_F3  175
#define NOTE_FS3 185
#define NOTE_G3  196
#define NOTE_GS3 208
#define NOTE_A3  220
#define NOTE_AS3 233
#define NOTE_B3  247
#define NOTE_C4  262
#define NOTE_CS4 277
#define NOTE_D4  294
#define NOTE_DS4 311
#define NOTE_E4  330
#define NOTE_F4  349
#define NOTE_FS4 370
#define NOTE_G4  392
#define NOTE_GS4 415
#define NOTE_A4  440
#define NOTE_AS4 466
#define NOTE_B4  494
#define NOTE_C5  523
#define NOTE_CS5 554
#define NOTE_D5  587
#define NOTE_DS5 622
#define NOTE_E5  659
#define NOTE_F5  698
#define NOTE_FS5 740
#define NOTE_G5  784
#define NOTE_GS5 831
#define NOTE_A5  880
#define NOTE_AS5 932
#define NOTE_B5  988
#define NOTE_C6  1047
#define NOTE_CS6 1109
#define NOTE_D6  1175
#define NOTE_DS6 1245
#define NOTE_E6  1319
#define NOTE_F6  1397
#define NOTE_FS6 1480
#define NOTE_G6  1568
#define NOTE_GS6 1661
#define NOTE_A6  1760
#define NOTE_AS6 1865
#define NOTE_B6  1976
#define NOTE_C7  2093
#define NOTE_CS7 2217
#define NOTE_D7  2349
#define NOTE_DS7 2489
#define NOTE_E7  2637
#define NOTE_F7  2794
#define NOTE_FS7 2960
#define NOTE_G7  3136
#define NOTE_GS7 3322
#define NOTE_A7  3520
#define NOTE_AS7 3729
#define NOTE_B7  3951
#define NOTE_C8  4186
#define NOTE_CS8 4435
#define NOTE_D8  4699
#define NOTE_DS8 4978
 
#define melodyPin 4

// Fur Elise --> Melody
int melody[] = {
  NOTE_E5, NOTE_DS5, NOTE_E5, NOTE_DS5,
  NOTE_E5, NOTE_B4, NOTE_D5, NOTE_C5,
  NOTE_A4, NOTE_C4, NOTE_E4, NOTE_A4,
  NOTE_B4, NOTE_E4, NOTE_GS4, NOTE_B4,
  
  NOTE_C5, NOTE_E4, NOTE_E5, NOTE_DS5,
  NOTE_E5, NOTE_DS5, NOTE_E5, NOTE_B4,
  NOTE_D5, NOTE_C5, NOTE_A4, NOTE_C4,
  NOTE_E4, NOTE_A4, NOTE_B4, NOTE_E4,
  
  NOTE_C5, NOTE_B4, NOTE_A4, NOTE_B4,
  NOTE_C5, NOTE_D5, NOTE_E5, NOTE_G4,
  NOTE_F5, NOTE_E5, NOTE_D5, NOTE_F4,
  NOTE_E5, NOTE_D5, NOTE_C5, NOTE_E4,
  
  NOTE_D5, NOTE_C5, NOTE_B4, NOTE_E4,
  NOTE_E5, NOTE_E4, NOTE_E5, NOTE_E4,
  NOTE_E5, NOTE_E4, NOTE_E5, NOTE_DS4,
  NOTE_E5, NOTE_D4, NOTE_E5, NOTE_DS4,
  
  NOTE_E5, NOTE_B4, NOTE_D5, NOTE_C5,
  NOTE_A4, NOTE_C4, NOTE_E4, NOTE_A4,
  NOTE_B4, NOTE_E4, NOTE_GS4, NOTE_B4,
  NOTE_C5, NOTE_E4, NOTE_E5, NOTE_DS5,

  NOTE_E5, NOTE_DS5, NOTE_E5, NOTE_B4,
  NOTE_D5, NOTE_C5, NOTE_A4, NOTE_C4,
  NOTE_E4, NOTE_A4, NOTE_B4, NOTE_E4,
  NOTE_C5, NOTE_B4, NOTE_A4, 0,
  
};

// Main tempo of 'Fur Elise'
int tempo[] = {
  9, 9, 9, 9,
  9, 9, 9, 9,
  3, 9, 9, 9,
  3, 9, 9, 9,

  3, 9, 9, 9,
  9, 9, 9, 9,
  9, 9, 3, 9,
  9, 9, 3, 9,

  9, 9, 3, 9,
  9, 9, 3, 9,
  9, 9, 3, 9,
  9, 9, 3, 9,

  9, 9, 9, 9,
  9, 9, 9, 9,
  9, 9, 9, 9,
  9, 9, 9, 9,

  9, 9, 9, 9,
  3, 9, 9, 9,
  3, 9, 9, 9,
  3, 9, 9, 9,

  9, 9, 9, 9,
  9, 9, 3, 9,
  9, 9, 3, 8,
  8, 8, 1, 9,
};

void setup(void)
{
  pinMode(4, OUTPUT); // Buzzer Pin
  pinMode(8, OUTPUT); // Led Output
}
void loop(){
  sing(1);
}

int song = 0;
 
void sing(int s) {
  
  song = s;
  
  if (song == 1){
 
    Serial.println("'Fur Elise'");
    
    int size = sizeof(melody) / sizeof(int);
    
    for (int thisNote = 0; thisNote < size; thisNote++) {
      int noteDuration = 1000 / tempo[thisNote];
      buzz(melodyPin, melody[thisNote], noteDuration);
      
      int pauseBetweenNotes = noteDuration * 1.30;
      delay(pauseBetweenNotes);
      
      buzz(melodyPin, 0, noteDuration);
 
    }
  }
}
 
void buzz(int targetPin, long frequency, long length) {
  
  digitalWrite(6, HIGH);
  
  long delayValue = 1000000 / frequency / 2;
  long numCycles = frequency * length / 1000;
  
  for (long i = 0; i < numCycles; i++) {
    digitalWrite(targetPin, HIGH);
    delayMicroseconds(delayValue);
    digitalWrite(targetPin, LOW);
    delayMicroseconds(delayValue);
  }
  
  digitalWrite(6, LOW);
}