int speakerPin = 2; // speaker or MIDI out pin

// define LED pins (10 LEDs, reversed so lowest note is D12)
int ledPins[10] = {12, 11, 10, 9, 8, 7, 6, 5, 4, 3};

// TEMPO CONTROL — change this to make it faster/slower
int tempo = 100; // beats per minute

// TRANSPOSE CONTROL — shift all notes up/down in semitones
// e.g. 0 = normal pitch, -12 = down 1 octave, +12 = up 1 octave
#define TRANSPOSE  0

// note range that maps to the LEDs (these will be shifted by TRANSPOSE)
int minNote = 65; // F4
int maxNote = 77; // F5

// melody: MIDI note number and duration (base duration in ms)
int melody[][2] = {
  {65,500},{65,500},{65,500},{65,500},
  {77,500},{77,500},{77,500},{77,500},
  {76,500},{76,500},{72,500},{74,500},
  {76,500},{76,500},{77,500},{77,500},
  {70,500},{70,500},{70,500},{70,500},
  {74,500},{74,500},{74,500},{74,500},
  {72,500},{72,500},{72,500},{72,500},
  {72,500},{72,500},{72,500},{72,500},
  {74,500},{74,500},{74,500},{74,500},
  {70,500},{70,500},{70,500},{70,500},
  {69,500},{69,500},{65,500},{67,500},
  {69,500},{69,500},{71,500},{71,500},
  {67,500},{64,500},{65,500},{67,500},
  {69,500},{69,500},
  {65,500},{65,500},{65,500},{65,500},
  {65,500},{65,500},{72,500},{72,500},
  {69,500},{72,500},{69,500},{72,500},
  {69,500},{72,500},{69,500},{72,500},
  {70,500},{72,500},{70,500},{72,500},
  {70,500},{72,500},{70,500},{72,500},
  {74,500},{74,500},{74,500},{74,500},
  {74,500},{74,500},{74,500},{74,500},
  {74,500},{74,500},{74,500},{74,500},
  {74,500},{74,500},{72,500},{72,500},
  {69,500},{72,500},{69,500},{72,500},
  {69,500},{72,500},{69,500},{72,500},
  {71,500},{74,500},{71,500},{74,500},
  {71,500},{74,500},{71,500},{74,500},
  {76,500},{76,500},{76,500},{76,500},
  {76,500},{76,500},{76,500},{76,500},
  {67,500},{67,500},{67,500},{67,500},
  {70,500},{70,500},{70,500},{70,500},
  {65,500},{65,500},{65,500},{65,500},
  {77,500},{77,500},{77,500},{77,500},
  {76,500},{76,500},{72,500},{74,500},
  {76,500},{76,500},{77,500},{77,500},
  {70,500},{70,500},{70,500},{70,500},
  {74,500},{74,500},{74,500},{74,500},
  {72,500},{72,500},{72,500},{72,500},
  {72,500},{72,500},{72,500},{72,500},
  {74,500},{74,500},{74,500},{74,500},
  {70,500},{70,500},{70,500},{70,500},
  {69,500},{69,500},{65,500},{67,500},
  {69,500},{69,500},{71,500},{71,500},
  {67,500},{64,500},{65,500},{67,500},
  {69,500},{69,500},
  {65,500},{65,500},{65,500},{65,500},
  {65,500},{65,500},{72,500},{72,500},
  {69,500},{72,500},{69,500},{72,500},
  {69,500},{72,500},
  {71,500},{72,500},{74,500},{76,500},
  {77,500},{77,500},{77,500},{77,500}
};

int melodyLength = sizeof(melody) / sizeof(melody[0]);

void setup() {
  Serial.begin(9600);
  
  // set LED pins as output
  for (int i = 0; i < 10; i++) {
    pinMode(ledPins[i], OUTPUT);
    digitalWrite(ledPins[i], LOW);
  }
  pinMode(speakerPin, OUTPUT);
}

void loop() {
  float tempoFactor = 120.0 / tempo; // tempo scaling

  for (int i = 0; i < melodyLength; i++) {
    int note = melody[i][0] + TRANSPOSE; // apply transpose
    int baseDuration = melody[i][1];
    int duration = baseDuration * tempoFactor / 2; // shorten for rhythm

    // Map note to LED index, clamp to valid range (with transpose)
    int ledIndex = map(note, minNote + TRANSPOSE, maxNote + TRANSPOSE, 0, 9);
    ledIndex = constrain(ledIndex, 0, 9);

    // Light LED
    digitalWrite(ledPins[ledIndex], HIGH);

    // Calculate frequency and play note
    float freq = 440.0 * pow(2.0, (note - 69) / 12.0);
    tone(speakerPin, freq);
    Serial.println(freq);
    delay(duration);

    // Turn off LED
    digitalWrite(ledPins[ledIndex], LOW);
  }

  noTone(speakerPin);
  delay(1000); // brief pause before repeating
}