DIY Christmas Decor Project: http://e-gizmo.com/wp/2018/10/27/diy-christmas-decoration-project/

Christmas_Songs.ino

/*

 DIY Christmas Song Sketch
 
 Using gizDuino LIN-UNO (Arduino UNO).

 
 */
#include <eGizmo_SerialLCD.h>
#include "pitches.h"

#define melodyPin 9

//For Arduino UNO or Gizduino V users
/*
SoftwareSerial mySerial(2,3);
 eGizmo_SerialLCD mainDisplay(&myserial);
 */

//For MEGA, X, and Plus users
eGizmo_SerialLCD mainDisplay(&Serial, 2, 16); //Set to 2x16 LCD

// Jingle Bells

int melody[] = {
  NOTE_E5, NOTE_E5, NOTE_E5,
  NOTE_E5, NOTE_E5, NOTE_E5,
  NOTE_E5, NOTE_G5, NOTE_C5, NOTE_D5,
  NOTE_E5,
  NOTE_F5, NOTE_F5, NOTE_F5, NOTE_F5,
  NOTE_F5, NOTE_E5, NOTE_E5, NOTE_E5, NOTE_E5,
  NOTE_E5, NOTE_D5, NOTE_D5, NOTE_E5,
  NOTE_D5, NOTE_G5
};

int tempo[] = {
  8, 8, 4,
  8, 8, 4,
  8, 8, 8, 8,
  2,
  8, 8, 8, 8,
  8, 8, 8, 16, 16,
  8, 8, 8, 8,
  4, 4
};

// We wish you a merry Christmas

int wish_melody[] = {
  NOTE_B3, 
  NOTE_F4, NOTE_F4, NOTE_G4, NOTE_F4, NOTE_E4,
  NOTE_D4, NOTE_D4, NOTE_D4,
  NOTE_G4, NOTE_G4, NOTE_A4, NOTE_G4, NOTE_F4,
  NOTE_E4, NOTE_E4, NOTE_E4,
  NOTE_A4, NOTE_A4, NOTE_B4, NOTE_A4, NOTE_G4,
  NOTE_F4, NOTE_D4, NOTE_B3, NOTE_B3,
  NOTE_D4, NOTE_G4, NOTE_E4,
  NOTE_F4
};

int wish_tempo[] = {
  4,
  4, 8, 8, 8, 8,
  4, 4, 4,
  4, 8, 8, 8, 8,
  4, 4, 4,
  4, 8, 8, 8, 8,
  4, 4, 8, 8,
  4, 4, 4,
  2
};

// Santa Claus is coming to town

int santa_melody[] = {
  NOTE_G4,
  NOTE_E4, NOTE_F4, NOTE_G4, NOTE_G4, NOTE_G4,
  NOTE_A4, NOTE_B4, NOTE_C5, NOTE_C5, NOTE_C5,
  NOTE_E4, NOTE_F4, NOTE_G4, NOTE_G4, NOTE_G4,
  NOTE_A4, NOTE_G4, NOTE_F4, NOTE_F4,
  NOTE_E4, NOTE_G4, NOTE_C4, NOTE_E4,
  NOTE_D4, NOTE_F4, NOTE_B3,
  NOTE_C4
};

int santa_tempo[] = {
  8,
  8, 8, 4, 4, 4,
  8, 8, 4, 4, 4,
  8, 8, 4, 4, 4,
  8, 8, 4, 2,
  4, 4, 4, 4,
  4, 2, 4,
  1
};

int SW_ONE = 0;
int SW_TWO = 0;
int SW_THREE = 0;

#define LED_INDICATOR 10
#define BUZZER 9
#define SONG1 2
#define SONG2 3 
#define SONG3 4
#define SONG1_LED 5
#define SONG2_LED 6
#define SONG3_LED 7


void setup(){
  //Initialize
  mainDisplay.begin();

  //mainDisplay.print(message, row, column);
  //note: you can place your message/row/column in any positions
  mainDisplay.print("Hello", 1,6);
  mainDisplay.print("World!", 2,6);

  delay(2000); //2 seconds delay time

  mainDisplay.printOver("EVERYONE!", 2,6);

  delay(2000);  //2 seconds delay time

  //Clear all
  mainDisplay.clear();

  delay(2000);  //2 seconds delay time

  mainDisplay.scroll(1,"MERRY CHRISTMAS 2018!!!"); // Message Scrolling from left to right on the 1st  row

  delay(1000);  //1 sec delay time

  mainDisplay.scroll(2,"FROM: e-Gizmo Mechatronix Central"); // Message Scrolling from left to right on the 2nd  row
  //mainDisplay.print("SerialLCD Sample", 3,0); //Display message on 3rd row
  //mainDisplay.print("**4x20 & 2x16 LCD**", 4,0); //Display message on 4th row

  //  for(int i = 0; i <=10; i++){
  //   mainDisplay.pinMode(i,OUTPUT);
  // }
  mainDisplay.pinMode(LED_INDICATOR,OUTPUT);
  pinMode(BUZZER,OUTPUT);
  pinMode(SONG1,INPUT);
  pinMode(SONG2,INPUT);
  pinMode(SONG3,INPUT);
  mainDisplay.pinMode(SONG1_LED,INPUT);
  mainDisplay.pinMode(SONG2_LED,INPUT);
  mainDisplay.pinMode(SONG3_LED,INPUT);
   mainDisplay.digitalWrite(SONG1_LED,LOW);
  mainDisplay.digitalWrite(SONG2_LED,LOW);
    mainDisplay.digitalWrite(SONG3_LED,LOW);
}

void loop(){

  SW_ONE = digitalRead(SONG1);
  SW_TWO= digitalRead(SONG2);
  SW_THREE =digitalRead(SONG3);
  if (SW_ONE == HIGH) {
    MUSIC(1);
  } 
  else if (SW_TWO == HIGH) {
    MUSIC(2);
  } 
  else if (SW_THREE == HIGH) {
    MUSIC(3);
  }

}
int SONG = 0;
void MUSIC(int s) {
  // iterate over the notes of the melody:
  SONG = s;
  if (SONG == 3) {
    Serial.println(" 'We wish you a Merry Christmas'");
    mainDisplay.digitalWrite(SONG1_LED,HIGH);
    mainDisplay.digitalWrite(SONG2_LED,LOW);
    mainDisplay.digitalWrite(SONG3_LED,LOW);
    int size = sizeof(wish_melody) / sizeof(int);
    for (int thisNote = 0; thisNote < size; thisNote++) {

      // to calculate the note duration, take one second
      // divided by the note type.
      //e.g. quarter note = 1000 / 4, eighth note = 1000/8, etc.
      int noteDuration = 1000 / wish_tempo[thisNote];

      BUZZ(melodyPin, wish_melody[thisNote], noteDuration);

      // to distinguish the notes, set a minimum time between them.
      // the note's duration + 30% seems to work well:
      int pauseBetweenNotes = noteDuration * 1.30;
      delay(pauseBetweenNotes);

      // stop the tone playing:
      BUZZ(melodyPin, 0, noteDuration);

    }
  } 
  else if (SONG == 2) {
    Serial.println(" 'Santa Claus is coming to town'");
    mainDisplay.digitalWrite(SONG1_LED,LOW);
    mainDisplay.digitalWrite(SONG2_LED,HIGH);
    mainDisplay.digitalWrite(SONG3_LED,LOW);
    int size = sizeof(santa_melody) / sizeof(int);
    for (int thisNote = 0; thisNote < size; thisNote++) {

      // to calculate the note duration, take one second
      // divided by the note type.
      //e.g. quarter note = 1000 / 4, eighth note = 1000/8, etc.
      int noteDuration = 900 / santa_tempo[thisNote];

      BUZZ(melodyPin, santa_melody[thisNote], noteDuration);

      // to distinguish the notes, set a minimum time between them.
      // the note's duration + 30% seems to work well:
      int pauseBetweenNotes = noteDuration * 1.30;
      delay(pauseBetweenNotes);

      // stop the tone playing:
      BUZZ(melodyPin, 0, noteDuration);

    }
  } 
  else {

    Serial.println(" 'Jingle Bells'");
    mainDisplay.digitalWrite(SONG1_LED,LOW);
    mainDisplay.digitalWrite(SONG2_LED,LOW);
    mainDisplay.digitalWrite(SONG3_LED,HIGH);
    int size = sizeof(melody) / sizeof(int);
    for (int thisNote = 0; thisNote < size; thisNote++) {

      // to calculate the note duration, take one second
      // divided by the note type.
      //e.g. quarter note = 1000 / 4, eighth note = 1000/8, etc.
      int noteDuration = 1000 / tempo[thisNote];

      BUZZ(melodyPin, melody[thisNote], noteDuration);

      // to distinguish the notes, set a minimum time between them.
      // the note's duration + 30% seems to work well:
      int pauseBetweenNotes = noteDuration * 1.30;
      delay(pauseBetweenNotes);

      // stop the tone playing:
      BUZZ(melodyPin, 0, noteDuration);

    }
  }
}

void BUZZ(int targetPin, long frequency, long length) {
  mainDisplay.digitalWrite(LED_INDICATOR, HIGH);
  long delayValue = 1000000 / frequency / 2; // calculate the delay value between transitions
  //// 1 second's worth of microseconds, divided by the frequency, then split in half since
  //// there are two phases to each cycle
  long numCycles = frequency * length / 1000; // calculate the number of cycles for proper timing
  //// multiply frequency, which is really cycles per second, by the number of seconds to
  //// get the total number of cycles to produce
  for (long i = 0; i < numCycles; i++) { // for the calculated length of time...
    digitalWrite(BUZZER, HIGH); // write the buzzer pin high to push out the diaphram
    delayMicroseconds(delayValue); // wait for the calculated delay value
    digitalWrite(BUZZER, LOW); // write the buzzer pin low to pull back the diaphram
    delayMicroseconds(delayValue); // wait again or the calculated delay value
  }
  mainDisplay.digitalWrite(LED_INDICATOR, LOW); 

}