Colchester HackSpace (@ColchHackSpace) HAXMAS challenge

HAXMAS.ino

/*
  Colchester HackSpace (@ColchHackSpace) HAXMAS!!!
  
  
  heavily based on blink
  tunes provided by https://gist.github.com/elubow/7844436
 
  /This/ example code is in the public domain.
  
  Power to v3.3
  LEDs on pins 10-13
  Speaker on pin 5
*/


/**************************************************************
** Setup chasing lights. 
***************************************************************/
int leds[] = { 13, 12, 11, 10 }; 
int maxLeds = 4;

/**************************************************************
** Setup speaker
***************************************************************/
int speakerPin = 5;
int length = 26;
char notes[] = "eeeeeeegcde fffffeeeeddedg";
int beats[] = { 1, 1, 2, 1, 1, 2, 1, 1, 1, 1, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2};
int tempo = 200;

void playTone(int tone, int duration) {
  for (long i = 0; i < duration * 1000L; i += tone * 2) {
    digitalWrite(speakerPin, HIGH);
    delayMicroseconds(tone);
    digitalWrite(speakerPin, LOW);
    delayMicroseconds(tone);
  }
}

void playNote(char note, int duration) {
  char names[] = { 'c', 'd', 'e', 'f', 'g', 'a', 'b', 'C' };
  int tones[] = { 1915, 1700, 1519, 1432, 1275, 1136, 1014, 956 };
  
  // play the tone corresponding to the note name
  for (int i = 0; i < 8; i++) {
    if (names[i] == note) {
      playTone(tones[i], duration);
    }
  }
}

/**************************************************************
** Setup arduino pins
***************************************************************/
void setup() {

 Serial.begin(9600);  
  // initialize the digital pin as an output.   
 for(int i = 0; i < maxLeds; i++) {
   pinMode(leds[i], OUTPUT);
 }

  pinMode(speakerPin, OUTPUT);
  
  randomSeed(analogRead(0));
}

int randNum;
/**************************************************************
** Main routine
***************************************************************/
void loop() {
//  for(int i = 0; i < maxLeds; i++) {
//    digitalWrite(leds[i], HIGH);   // turn the LED on (HIGH is the voltage level)
//    delay(500);               // wait for a second
//    digitalWrite(leds[i], LOW);    // turn the LED off by making the voltage LOW
//    delay(500);               // wait for a second
//  }

  for (int i = 0; i < length; i++) {
    randNum = random(0,4);
    Serial.println(randNum);
    if (notes[i] == ' ') {
      delay(beats[i] * tempo); // rest
    } else {
      playNote(notes[i], beats[i] * tempo);
      digitalWrite(leds[randNum], HIGH);
      delay(100);
    }
    
    // pause between notes
    delay(tempo / 2);
   digitalWrite(leds[randNum], LOW); 
  }
}