#include <LiquidCrystal_I2C.h>

#define I2C_ADDR    0x27
#define LCD_COLUMNS 20
#define LCD_LINES   4

LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

#include "pitches.h"

#define SPEAKER_PIN 8

const uint8_t buttonPins[] = { 12, 11, 10, 9, 7, 6, 5, 4 };
const int buttonTones[] = {
  NOTE_C4, NOTE_D4, NOTE_E4, NOTE_F4,
  NOTE_G4, NOTE_A4, NOTE_B4, NOTE_C5
};
const int numTones = sizeof(buttonPins) / sizeof(buttonPins[0]);

void setup() {
   lcd.init();
  lcd.backlight();

lcd.setCursor(3, 0);
lcd.print("Arduino Piano");
lcd.setCursor(2, 1);
lcd.print("buy and try");
delay(500);

  for (uint8_t i = 0; i < numTones; i++) {
    pinMode(buttonPins[i], INPUT_PULLUP);
  }
  pinMode(SPEAKER_PIN, OUTPUT);
}

void loop() {
  int pitch = 0;
  for (uint8_t i = 0; i < numTones; i++) {
    if (digitalRead(buttonPins[i]) == LOW) {
      pitch = buttonTones[i];
    }
  }
  if (pitch) {
    tone(SPEAKER_PIN, pitch);
    lcd.clear();
    lcd.setCursor(2, 0);
    lcd.print("Pitch:");
    lcd.setCursor(8, 0);
lcd.print(pitch);

  } else {
    noTone(SPEAKER_PIN);
  }
}