const int pot = A5;
const int piezo = 13;
int led, val, value, tono;
const int gap = 100;
unsigned long previous = 0;
bool flag = 0;

// TONES: note, period & frequency.
int c = 3830; // 261 Hz
int d = 3400; // 294 Hz
int e = 3038; // 329 Hz
int f = 2864; // 349 Hz
int g = 2550; // 392 Hz
int A = 2272; // 440 Hz
int B = 2028; // 493 Hz
int C = 1912; // 523 Hz
int D = 1704; // 587 Hz
int E = 1517; // 659 Hz
int F = 1432; // 698 Hz
int G = 1275; // 784 Hz

int note[] = {c,d,e,f,g,A,B,C,D,E,F,G};

void setup() {
  for (led = 2; led <= 12; led++)
    pinMode(led, OUTPUT);
    pinMode(pot, INPUT);
  Serial.begin(9600);
}

void loop() {
  val = analogRead(piezo);
  value = map(val, 0, 1023, 1, 12);

    for (led = 2; led <= 12; led++) {
      if ((led > value-2) && (led < value+2))
        digitalWrite(led, HIGH);
      else
        digitalWrite(led, LOW);
    }

  tono = map(val, 0, 1023, 11, 0);

  if (millis() - previous >= gap) {
    previous = millis();
    if (flag == 0) {
      flag = 1;
      tone(piezo, note[tono]);
    }
    else {
      flag = 0;
      noTone(piezo);
    }
  }

}