I created a three note piano. Each button corresponds to a different note and the note is played as long as the button is being pressed. I attempted to play Hot Cross buns with my project.

Link to video: https://drive.google.com/file/d/0B35Qci0Dl57aYXZTUWtIMjhVcnc/view?usp=sharing
#include "pitches.h"

int buttonState = 0; // Reading the button status

// Notes to play, corresponding to the 3 buttons
int notes[] = {
NOTE_B4, NOTE_A4, NOTE_C4
};

void setup() {

}

void loop() {
// There are three buttons wired to Digital Output 0, 1 and 2
// The speaker is wired to Digital Output 8
for (int i = 0; i < 3; i++) {
// Reads the state of the button
buttonState = digitalRead(i);

// If the button is pressed the note corresponding to the
// button pressed is played
if (buttonState == HIGH) {
tone(8, notes[i]);
}
//If button is not pressed, nothing is played
else {
noTone(8);
}
}
}

/*************************************************
* pitches.h
* Public Constants
* Taken from Arduino Documentation
*************************************************/

#define NOTE_C4 262
#define NOTE_A4 440
#define NOTE_B4 494