Need this to play music

Question

Game dev class. Trying to understand what i did wrong here. Did I add the wrong thing, or do i have it at the wrong place. my goal was to add music.

#include "allegro5/allegro.h"
#include <allegro5/allegro_image.h>
#include <allegro5/allegro_font.h>
#include <allegro5/allegro_ttf.h>
#include <allegro5/allegro_native_dialog.h>
#include <stdio.h>
#include <string>
#include <allegro5\allegro_audio.h>
#include <allegro5\allegro_acodec.h>


#define FPS 60
#define SCREEN_WIDTH 800
#define SCREEN_HEIGHT 600
#define BLACK al_map_rgb(0, 0, 0)
#define WHITE al_map_rgb(255, 255, 255)

//Prototypes
bool initializeAllegro();

//Essential Allegro pointers
ALLEGRO_DISPLAY *display = NULL;
ALLEGRO_EVENT_QUEUE *eventQueue = NULL;
ALLEGRO_TIMER *timer = NULL;
ALLEGRO_FONT *arial14;

int main()
{
    ALLEGRO_BITMAP *backgroundImage;    //Bitmap for the background image(star field)
    int backgroundImageWidth = 0, backgroundImageHeight = 0;

    bool redrawRequired = true;
    //Using std:string for name, so length is not a factor
    std::string userName = "";
    std::string prompt1 = "Enter your Player's name below";
    std::string prompt2 = "(Letters & digits only. Backspace to erase.)";
    std::string prompt3 = "Press Enter to accept...";
    std::string prompt4 = "Press Escape to exit...";
    char keyToAdd = ' ';
    bool enteringUserName = true;
    bool quit = false;

    //Initialize allegro, etc
    if (!initializeAllegro()) return -1;

    //load the arial font
    arial14 = al_load_font("arial-mt-black.ttf", 14, 0);
    if (!arial14)
    {
        return -3;
    }
    //test running music
    al_init_acodec_addon();

    ALLEGRO_SAMPLE *song = al_load_sample("hideandseek.wav");
    ALLEGRO_SAMPLE_INSTANCE *songInstance = al_create_sample_instance(song);
    al_set_sample_instance_playmode(songInstance, ALLEGRO_PLAYMODE_LOOP);
    al_attach_sample_instance_to_mixer(songInstance, al_get_default_mixer());

    //Load the background picture
    if (!(backgroundImage = al_load_bitmap("starbackground.bmp")))
    {
        return -5;
    }

    //Get dimensions of the background image
    backgroundImageWidth = al_get_bitmap_width(backgroundImage);
    backgroundImageHeight = al_get_bitmap_height(backgroundImage);

    //Set the back buffer as the drawing bitmap for the display
    al_set_target_bitmap(al_get_backbuffer(display));

    //Initialize the event queue
    eventQueue = al_create_event_queue();
    if (!eventQueue)
    {
        al_destroy_display(display);
        al_destroy_timer(timer);
        return -1;
    }

    //Register events as arriving from these sources:  display, timer, keyboard
    al_register_event_source(eventQueue, al_get_display_event_source(display));
    al_register_event_source(eventQueue, al_get_timer_event_source(timer));
    al_register_event_source(eventQueue, al_get_keyboard_event_source());

    al_flip_display();

    //play song
    al_play_sample_instance(songInstance);

    //Start up the timer.  Don't do this until just before the game is to start!
    al_start_timer(timer);

    //This would be a loop solely for entering the user's name, not starting the game
    //Allegro keycodes are laid out as follows.  (Full set of key codes is included in keycodes.h)
    //Key codes for capital letters are 1 - 26 for A - Z
    //Digit values are 27 - 36 for the top digits (0 - 9), and 37 - 46 for the keypad
    while (!quit)
    {
        ALLEGRO_EVENT evt;
        //Wait for one of the allegro-defined events
        al_wait_for_event(eventQueue, &evt);

        //An event was generated. Check for all possible event types
        switch (evt.type)
        {
            case ALLEGRO_EVENT_KEY_CHAR:
                if (evt.keyboard.keycode >= 1 && evt.keyboard.keycode <= 26) //It's a capital letter
                {
                    //Convert to ASCII capital
                    keyToAdd = *al_keycode_to_name(evt.keyboard.keycode);
                    userName += keyToAdd;
                }
                else if (evt.keyboard.keycode >= 27 && evt.keyboard.keycode <= 36)
                {
                    //Convert to digit
                    keyToAdd =  evt.keyboard.keycode + 21;
                    userName += keyToAdd;
                }
                //Handle digits on keypad
                else if (evt.keyboard.keycode >= 37 && evt.keyboard.keycode <= 46)
                {
                    //Convert to digit
                    keyToAdd =  evt.keyboard.keycode + 11;
                    userName += keyToAdd;
                }
                else //Handle a few other keys
                {
                    switch(evt.keyboard.keycode)
                    {   
                        case ALLEGRO_KEY_BACKSPACE: 
                            if (userName.length() > 0)
                                userName = userName.substr(0, userName.length() - 1);
                            break;

                        //Enter key stops username entry
                        case ALLEGRO_KEY_ENTER:
                        case ALLEGRO_KEY_PAD_ENTER:
                            enteringUserName = false;
                            break;
                        case ALLEGRO_KEY_ESCAPE:
                            quit = true;
                            break;
                    }
                }
                break;

            case ALLEGRO_EVENT_DISPLAY_CLOSE:
                quit = true;
                break;

            case ALLEGRO_EVENT_TIMER:
                redrawRequired = true;
                break;

        }//END switch evt.type

        //Rerender the entire scene
        if (redrawRequired && al_is_event_queue_empty(eventQueue))
        {
            redrawRequired = false;

            al_clear_to_color(BLACK);   //Just in case

            //Draw background
            al_draw_scaled_bitmap(backgroundImage, 0, 0, backgroundImageWidth, backgroundImageHeight,
                0, 0, SCREEN_WIDTH, SCREEN_HEIGHT, 0);

            //Prompt for name to be entered
            al_draw_textf (arial14, WHITE, 0, 30, 0, "%s", prompt1.c_str());
            al_draw_textf (arial14, WHITE, 0, 50, 0, "%s", prompt2.c_str());
            if (userName.length() > 0)
            {
                if (enteringUserName)
                {
                    al_draw_textf (arial14, WHITE, 0, 70, 0, "%s", userName.c_str());
                    al_draw_textf (arial14, WHITE, 0, 90, 0, "%s", prompt3.c_str());
                }
                else
                {
                    al_draw_textf (arial14, WHITE, 0, 70, 0, "You entered your name as-->%s", userName.c_str());
                }
            }

            al_draw_textf(arial14, WHITE, 0, 400, 0, "%s", prompt4.c_str());

            al_flip_display();
        }//END rendering the screen

    }//END input Loop

    //Release all dynamically allocated memory
    al_destroy_bitmap(backgroundImage);
    al_destroy_font(arial14);
    al_destroy_timer(timer);
    al_destroy_display(display);
    al_destroy_event_queue(eventQueue);
    //destroy songs
    al_destroy_sample(song);
    al_destroy_sample_instance(songInstance);

    return 0;
}//END main

//Take care of Allegro initialization tasks
//Return false if any fail.
bool initializeAllegro()
{
    bool success = true;

    //Init basic environment
    if (!al_init())
    {
        al_show_native_message_box(NULL, "ERROR", "Allegro failed to initialize!", NULL, NULL, NULL);
        success = false;
    }

    //Initialize keyboard input
    if (!al_install_keyboard())
    {
        al_show_native_message_box(NULL, "ERROR", "Keyboard failed to initialize!", NULL, NULL, NULL);
        success = false;
    }

    //Initialize timer
    timer = al_create_timer(1.0 / FPS);
    if (!timer)
    {
        al_show_native_message_box(NULL, "ERROR", "Timer failed to initialize!", NULL, NULL, NULL);
        success = false;
    }

    //Initialize display
    display = al_create_display(SCREEN_WIDTH, SCREEN_HEIGHT);
    if (!display)
    {
        al_show_native_message_box(NULL, "ERROR", "Display failed to initialize!", NULL, NULL, NULL);
        success = false;
    }

    //Initialize the image mechanism
    if (!al_init_image_addon())
    {
        al_show_native_message_box(NULL, "ERROR", "Image addon failed to initialize!", NULL, NULL, NULL);
        success = false;
    }

    al_init_font_addon();
    al_init_ttf_addon();

    return success;
}//END initializeAllegro

Any wav file should work. i get the error message -

First-chance exception at 0x0F196486 (allegro-5.0.10-monolith-md-debug.dll) in User Input Project.exe: 0xC0000005: Access violation reading location 0x00000000. Unhandled exception at 0x0F196486 (allegro-5.0.10-monolith-md-debug.dll) in User Input Project.exe: 0xC0000005: Access violation reading location 0x00000000.

The program '[9596] User Input Project.exe' has exited with code 0 (0x0).

Answer 1

I mentioned to step through things with a debugger in my comment, but the code smell here is this:

ALLEGRO_SAMPLE *song = al_load_sample("hideandseek.wav");
ALLEGRO_SAMPLE_INSTANCE *songInstance = al_create_sample_instance(song);

You should Definitely be checking for (song == NULL) before you call al_create_sample_instance()

If your path to the .WAV file is wrong or if the loading fails for any other reason, then al_load_sample() will return NULL, and you shouldn't be trying to do anything with song