#define a3f 208 // 208 Hz
#define b3f 233 // 233 Hz
#define b3 247 // 247 Hz
#define c4 261 // 261 Hz MIDDLE C
#define c4s 277 // 277 Hz
#define e4f 311 // 311 Hz
#define f4 349 // 349 Hz
#define a4f 415 // 415 Hz
#define b4f 466 // 466 Hz
#define b4 493 // 493 Hz
#define c5 523 // 523 Hz
#define c5s 554 // 554 Hz
#define e5f 622 // 622 Hz
#define f5 698 // 698 Hz
#define f5s 740 // 740 Hz
#define a5f 831 // 831 Hz

#define rest -1

// change these pins according to your setup
int piezo = 2;
int led = 3;

volatile int beatlength = 100; // determines tempo
float beatseparationconstant = 0.3;

int a; // part index
int b; // song index
int c; // lyric index

boolean flag; // play/pause

// Parts 1 and 2 (Intro)

int song1_intro_melody[] =
{c5s, e5f, e5f, f5, a5f, f5s, f5, e5f, c5s, e5f, rest, a4f, a4f};

int song1_intro_rhythmn[] =
{6, 10, 6, 6, 1, 1, 1, 1, 6, 10, 4, 2, 10};

// Parts 3 or 5 (Verse 1)

int song1_verse1_melody[] =
{ rest, c4s, c4s, c4s, c4s, e4f, rest, c4, b3f, a3f,
rest, b3f, b3f, c4, c4s, a3f, a4f, a4f, e4f,
rest, b3f, b3f, c4, c4s, b3f, c4s, e4f, rest, c4, b3f, b3f, a3f,
rest, b3f, b3f, c4, c4s, a3f, a3f, e4f, e4f, e4f, f4, e4f,
c4s, e4f, f4, c4s, e4f, e4f, e4f, f4, e4f, a3f,
rest, b3f, c4, c4s, a3f, rest, e4f, f4, e4f
};

int song1_verse1_rhythmn[] =
{ 2, 1, 1, 1, 1, 2, 1, 1, 1, 5,
1, 1, 1, 1, 3, 1, 2, 1, 5,
1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 3,
1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 4,
5, 1, 1, 1, 1, 1, 1, 1, 2, 2,
2, 1, 1, 1, 3, 1, 1, 1, 3
};

// Parts 4 or 6 (Chorus)

int song1_chorus_melody[] =
{ b4f, b4f, a4f, a4f,
f5, f5, e5f, b4f, b4f, a4f, a4f, e5f, e5f, c5s, c5, b4f,
c5s, c5s, c5s, c5s,
c5s, e5f, c5, b4f, a4f, a4f, a4f, e5f, c5s,
b4f, b4f, a4f, a4f,
f5, f5, e5f, b4f, b4f, a4f, a4f, a5f, c5, c5s, c5, b4f,
c5s, c5s, c5s, c5s,
c5s, e5f, c5, b4f, a4f, rest, a4f, e5f, c5s, rest
};

int song1_chorus_rhythmn[] =
{ 1, 1, 1, 1,
3, 3, 6, 1, 1, 1, 1, 3, 3, 3, 1, 2,
1, 1, 1, 1,
3, 3, 3, 1, 2, 2, 2, 4, 8,
1, 1, 1, 1,
3, 3, 6, 1, 1, 1, 1, 3, 3, 3, 1, 2,
1, 1, 1, 1,
3, 3, 3, 1, 2, 2, 2, 4, 8, 4
};


void setup() {
  pinMode(piezo, OUTPUT);
  pinMode(led, OUTPUT);
  digitalWrite(led, LOW);
  Serial.begin(9600);
  flag = true;
  a = 4;
  b = 0;
  c = 0;
}

void loop() {
  if (flag == true) {
    play();
  }
}

void play() {
  int notelength;
  if (a == 1 || a == 2) { // Intro
    // intro
    notelength = beatlength * song1_intro_rhythmn[b];
    if (song1_intro_melody[b] > 0) { // if not a rest, play note
      digitalWrite(led, HIGH);
      tone(piezo, song1_intro_melody[b], notelength);
    }

    b++;
    if (b >= sizeof(song1_intro_melody) / sizeof(int)) {
      a++;
      b = 0;
      c = 0;
    }
  } else if (a == 3 || a == 5) { // Verse 1
    // verse
    notelength = beatlength * 2 * song1_verse1_rhythmn[b];
    if (song1_verse1_melody[b] > 0) {
      digitalWrite(led, HIGH);
      tone(piezo, song1_verse1_melody[b], notelength);
      c++;
    }

    b++;
    if (b >= sizeof(song1_verse1_melody) / sizeof(int)) {
      a++;
      b = 0;
      c = 0;
    }
  } else if (a == 4 || a == 6) { //chorus
    // chorus
    notelength = beatlength * song1_chorus_rhythmn[b];
    if (song1_chorus_melody[b] > 0) {
      digitalWrite(led, HIGH);
      tone(piezo, song1_chorus_melody[b], notelength);
      c++;
    }

    b++;
    if (b >= sizeof(song1_chorus_melody) / sizeof(int)) {
      a++;
      b = 0;
      c = 0;
    }
  }
  delay(notelength); // necessary because piezo is on independent timer
  noTone(piezo);
  digitalWrite(led, LOW);
  delay(notelength * beatseparationconstant); // create separation between notes
  if (a == 7) { // loop back around to beginning of song
    a = 1;
  }
}