// Define the speaker pin
#define SPEAKER_PIN 8

// Define arrays for button pins and corresponding tones
const int buttonPins[] = { 12, 11, 10, 9, 7, 6, 5 }; 
// Change the numbers in the array above to the pins you are using
// These are the pins being used for this tutorial

const int buttonTones[] = {
  261.626, 293.665, 329.628, 349.228, 391.995, 440, 493.883
};

const int numTones = sizeof(buttonPins) / sizeof(buttonPins[0]);

void setup() {
  // Set up button pins as INPUT_PULLUP (with internal pull-up resistors)
  for (int i = 0; i < numTones; i++) {
    pinMode(buttonPins[i], INPUT_PULLUP);
  }
  // Set the speaker pin as OUTPUT
  pinMode(SPEAKER_PIN, OUTPUT);
}

void loop() {
  int pitch = 0;
  // Iterate through the button pins to check if any buttons are pressed
  for (int i = 0; i < numTones; i++) {
    if (digitalRead(buttonPins[i]) == LOW) { // If a button is pressed (LOW state)
      pitch += buttonTones[i]; // Add the corresponding tone to the pitch
    }
  }

  if (pitch) {
    // If pitch is not zero, play the tone on the speaker
    tone(SPEAKER_PIN, pitch);
  } else {
    // If no button is pressed, stop playing the tone
    noTone(SPEAKER_PIN);
  }
}